This research was supported by the German Federal Ministery for Education and Research (BMBF) funded &#8220;Virtual Liver Network&#8221;. I&#8217;d like to thank Frank Schubert and Rene Gumpert from the media center of Jena University Hospital for their help in producing the video and creating the animation and Isabel Jank for recording the audio.

Housing and all procedures carried out were in accordance with German Animal Welfare Legislation.
1. Sensors Calibration&#160;(Follow Manufacturer&#39;s Instructions for Sensors Calibration)
1.1) Millar catheter calibration. Pre-soak the tip of the catheter in sterile water or saline for 30 min prior to balance (zeroing) and calibration.
<ol>
	<li>Connect the millar sensor to the millar1 channel of bridge amplifier and insert the millar sensor tip into water column.</li>
	<li>Set the water column value to 0 cmH2O. In data analysis software window, choose bridge amplify and zero it. The baseline value 0 cmH2O can be set.</li>
	<li>Set the water column value to 20 cmH2O. Run data analysis software window progress, and stop. Choose &#8220;units&#8221; in the window of bridge amplify, set the baseline of 0 and 20 cmH2O accordingly. Adjust the &#8220;unit&#8221; to cmH2O.</li>
	<li>Calibrate the millar2 for measuring CAP in the same way (set two base line 90 and 110 cmH2O).</li>
</ol>
1.2) Blood flow probe calibration
<ol>
	<li>Put the probe into deionized water. Connect the probe with transonic flow probe system.</li>
	<li>In data analysis software window, choose Input amplify to zero the flow probe. Adjust the units.</li>
	<li>Press the button to &#8220;test channel&#8221; to collect the signal: if the signal has 3-4 bars, it means the signal is good. In case a good signal is acquired, the procedure can be continued.</li>
	<li>Press the button to &#8220;zero channel&#8221; and scale channel to see whether the value has been calibrated or not.</li>
	<li>Press the button to &#8220;measure channel&#8221; for later measuring.</li>
</ol>
2. Prepare the Mouse for the Surgical Procedure
<ol>
	<li>Place the mouse in an induction chamber and anesthetize the mouse with 2% isoflurane and 0.3 ml/min oxygen. The operation can be performed if the toe-pinch withdrawal&#160;reflex of the mouse is absent.</li>
	<li>Shave the fur of surgical regions, which include the left neck and abdomen.</li>
	<li>Place the mouse on the operation table and fix it using tapes. Use vet ointment on eyes to prevent dryness during the operation period.</li>
	<li>Place a gauze cushion under the neck for optimal exposure of the operation field of neck.</li>
	<li>Disinfect the operation field and place sterilized gauzes to cover the mouse only leaving the surgical field open.</li>
</ol>
3. Vital Parameters Measurement
<ol>
	<li>Insert the ECG needles subcutaneously into the paws of mouse.</li>
	<li>Place the respiratory sensor under the back of the mouse.</li>
	<li>Place the temperature probe into the rectum of the mouse.</li>
	<li>Record temperature, ECG and respiratory rate of the mouse in data analysis software.</li>
</ol>
4. Neck Operation for Systemic Cardiovascular Monitoring
4.1) Vessel dissection
<ol>
	<li>Identify the middle line of the neck, middle point of clavicle, the angle of mandible.</li>
	<li>Make a 2cm longitudinal incision from the angle of mandible to the middle point of clavicle which is 0.5cm to the left side of the middle line.</li>
	<li>Dissect the submandibular gland, turn it over and cover it with saline soaked gauze.</li>
	<li>Identify the jugular vein, dissect it and place three 6-0 silk sutures under the vein for later ligation and fixation.</li>
	<li>Identify the sternocleidomastoid muscle, separate it from the superior belly of omohyoid and posterior belly of digastric muscle, and pull it with a retractor for easy exposure of the carotid artery.</li>
	<li>Dissect the carotid artery and place three 6-0 silk sutures under the artery for later ligation and fixation.</li>
</ol>
4.2) Carotid artery blood flow measurement
<ol>
	<li>Place the transonic probe around the carotid artery, keep it stable, and optimize the contact using ultrasound gel or saline.</li>
	<li>Record blood flow velocity of the carotid artery as indicated on the small screen of the transonic device using data analysis software</li>
	<li>Remove the probe after completing the measurement</li>
</ol>
4.3) Carotid artery pressure measurement (CAP)
<ol>
	<li>Ligate the distal end of the carotid artery and clamp its proximal end.</li>
	<li>Place 2 fixing sutures around the carotid artery. Use 10-0 prolene for the stay suture.</li>
	<li>Make a small incision on the anterior wall of the vessel.</li>
	<li>Insert the millar catheter and fix it with pre-placed sutures.</li>
	<li>Record the CAP in data analysis software.</li>
</ol>
4.4) Jugular vein blood flow measurement
<ol>
	<li>Lift the jugular vein and place the transonic flow probe to measure the flow rate.</li>
	<li>Record the flow rate in data analysis software.</li>
</ol>
4.5) Central venous pressure measurement (CVP)
<ol>
	<li>Clamp the proximal end of the jugular vein and ligate the distal end.</li>
	<li>Cut a small incision using microscissors on the anterior wall of the vessel.</li>
	<li>Insert the fluid-filled catheter and fix it with the pre-placed suture lines.</li>
	<li>Record the CVP in data analysis software.</li>
</ol>
5. Abdominal Operation for Acquisition of Hepatic Hemodynamics
5.1) Vessel identification
<ol>
	<li>Make a transverse incision on the abdomen.</li>
	<li>Eventerate the intestines to the left side and cover with wet gauze.</li>
	<li>Identify the inferior vena cava, the portal vein, the common hepatic artery and the proper hepatic artery.</li>
	<li>Drop some warm saline in the abdomen and on the surface of the intestines every 5 min during the whole monitoring procedure.</li>
</ol>
5.2) Measurement of portal blood flow
<ol>
	<li>Dissect the portal vein.</li>
	<li>Place 6-0 silk under the portal vein to facilitate lifting of the vessel when placing the flow probe.</li>
	<li>Place the transonic flow probe around the portal vein and measure its blood flow rate.</li>
	<li>Record the blood flow rate of the portal vein.</li>
</ol>
5.3) Measurement of Common hepatic artery flow
<ol>
	<li>Dissect the common hepatic artery cautiously.</li>
	<li>Place one 6-0 silk suture around the vessel to facilitate lifting of the vessel.</li>
	<li>Place the flow probe around the artery.</li>
	<li>Measure its blood flow and acquire the data.</li>
</ol>
5.4) Measurement of portal vein pressure (PVP)
<ol>
	<li>Choose one branch of the mesenteric vein with few side branches, which drains straight into the portal vein.</li>
	<li>Ligate the distal end of the selected mesenteric vein. Make sure that ligation is close to the intestinal tube. Ligate its small branches</li>
	<li>Place 2 fixing sutures using 6-0 prolene around the vein. The key point of this procedure is to avoid touching the mesenteric artery when ligating the vein.</li>
	<li>Clamp the proximal end of the portal vein.</li>
	<li>Place 2 stay sutures using 10-0 prolene. Some bleeding will occur since the stay suture should penetrate the vascular wall of the fine mesenteric vein.</li>
	<li>Make a small incision on the vein using a microscissor obliquely at a 45 degrees angle.</li>
	<li>Insert the Millar catheter through the mesenteric vein into the portal vein and fix it</li>
	<li>Record the portal vein pressure. At the end of the procedure, sacrifice the mice by exsanguination under anesthesia.</li>
</ol>

<ol>
	<li>Albuszies, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+increased+cardiac+output+on+hepatic+and+intestinal+microcirculatory+blood+flow,+oxygenation,+and+metabolism+in+hyperdynamic+murine+septic+shock.">Effect of increased cardiac output on hepatic and intestinal microcirculatory blood flow, oxygenation, and metabolism in hyperdynamic murine septic shock.</a> Crit Care Med. 33 (10), 2332-2338 (2005).</li><li>Bernhard, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phosphatidylcholine+molecular+species+in+lung+surfactant:+composition+in+relation+to+respiratory+rate+and+lung+development.">Phosphatidylcholine molecular species in lung surfactant: composition in relation to respiratory rate and lung development.</a> Am. J. Respir. Cell Mol. Biol. 25 (6), 725-731 (2001).</li><li>Cheever, A. W., Warren, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Portal+vein+ligation+in+mice:+portal+hypertension,+collateral+circulation,+and+blood+flow.">Portal vein ligation in mice: portal hypertension, collateral circulation, and blood flow.</a> 18, 405-407 (1963).</li><li>Costa, G., Aguiar, B. G., Coelho, P. M., Cunha-Melo, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+increase+of+portal+pressure+during+the+acute+and+chronic+phases+of+murine+schistosomiasis+mansoni+and+its+reversibility+after+treatment+with+oxamniquine.">On the increase of portal pressure during the acute and chronic phases of murine schistosomiasis mansoni and its reversibility after treatment with oxamniquine.</a> Acta Trop. 89 (1), 13-16 (2003).</li><li>Cui, S., Shibamoto, T., Zhang, W., Takano, H., Kurata, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Venous+resistance+increases+during+rat+anaphylactic+shock.">Venous resistance increases during rat anaphylactic shock.</a> Shock. 29 (6), 733-739 (2008).</li><li>Geerts, A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+three+research+models+of+portal+hypertension+in+mice:+macroscopic,+histological+and+portal+pressure+evaluation.">Comparison of three research models of portal hypertension in mice: macroscopic, histological and portal pressure evaluation.</a> Int. J. Exp. Pathol. 89 (4), 251-263 (2008).</li><li>Huang, H., Deng, M., Jin, H., Dirsch, O., Dahmen, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraoperative+vital+and+haemodynamic+monitoring+using+an+integrated+multiple-channel+monitor+in+rats.">Intraoperative vital and haemodynamic monitoring using an integrated multiple-channel monitor in rats.</a> Lab Anim. 44 (3), 254-263 (2010).</li><li>Krege, J. H., Hodgin, J. B., Hagaman, J. R., Smithies, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+noninvasive+computerized+tail-cuff+system+for+measuring+blood+pressure+in+mice.">A noninvasive computerized tail-cuff system for measuring blood pressure in mice.</a> Hypertension. 25 (5), 1111-1115 (1995).</li><li>Kuga, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+and+local+autoregulation+of+cerebrovascular+blood+flow:+a+deep-brain+imaging+study+in+the+mouse.">Rapid and local autoregulation of cerebrovascular blood flow: a deep-brain imaging study in the mouse.</a> J. Physiol.. 587 (Pt 4), 745-752 (2009).</li><li>Muraki, T., Strain Kato, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=difference+in+the+effects+of+morphine+on+the+rectal+temperature+and+respiratory+rate+in+male+mice.">difference in the effects of morphine on the rectal temperature and respiratory rate in male mice.</a> Psychopharmacology (Berl). 89 (1), 60-64 (1986).</li><li>Nielsen, J. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Left+ventricular+volume+measurement+in+mice+by+conductance+catheter:+evaluation+and+optimization+of+calibration.">Left ventricular volume measurement in mice by conductance catheter: evaluation and optimization of calibration.</a> Am. J. Physiol Heart Circ. Physiol. 293 (1), H534-H540 (2007).</li><li>Sakamoto, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improvement+of+portal+hypertension+and+hepatic+blood+flow+in+cirrhotic+rats+by+oestrogen.">Improvement of portal hypertension and hepatic blood flow in cirrhotic rats by oestrogen.</a> Eur. J. Clin. Invest. 35 (3), 220-225 (2005).</li><li>Reverter, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+deep+sedation+on+the+accuracy+of+hepatic+and+portal+venous+pressure+measurements+in+patients+with+cirrhosis.">Impact of deep sedation on the accuracy of hepatic and portal venous pressure measurements in patients with cirrhosis.</a> Liver Int. 34 (1), 16-25 (2014).</li></ol>

The authors declare that they have no competing financial interests.

Monitoring of hepatic hemodynamics is an important research tool in hepatology and hepatobiliary surgery. Acquisition of hepatic hemodynamic data helps to characterize the effect of hepatobiliary procedures on the circulatory system. Acquisition of hepatic hemodynamic data is also needed to study the effect of drugs affecting portal pressure and portal flow, e.g., as needed in studies evaluating vasoactive drugs.
Despite the small size, the vital parameters, systemic and hepatic hemod...

The overall goal of this video was to demonstrate a real-time monitoring procedure for acquiring systemic and hepatic hemodynamic parameters. The rationale for developing this procedure is its great value for experimental interventions in mice&#160;that require&#160;obtaining systemic and hepatic hemodynamic parameters. The procedure can be applied to na&#239;ve animals and during or after a given hepato-biliary experimental surgical intervention, such as partial hepatectomy, portal vein ligation and liver transplantation.
Acquisition of hepatic hemodynamic data in rodents requires the proposed invasive procedure. Hepatic perfusion cannot be obtained non-invasively. However, there are alternatives for the acquisition of the systemic blood pressure. Monitoring techniques such as the tail cuff technique8 have been utilized for acquiring the blood pressure in both rats and mice. The tail cuff technique can be applied in conscious animals. When measuring the blood pressure, the animal needs to be placed and fixed in a specific uncomfortable position. In the manual of the tail-cuff device, the manufacturer states that mice may become nervous and stressed which may diminish the circulation in the tail. Under that circumstance, the peripheral blood pressure acquired in the tail may be much lower than the central blood pressure.
The full monitoring procedure was performed with an integrated multiple-channel monitor using a series of sensors for data acquisition. The blood pressure was obtained by inserting a catheter into the respective vessel after careful microsurgical dissection and exposure under the microscope. The flow rate was measured by placing a transonic flow probe around each vessel.
We already reported a similar intraoperative monitoring procedure for rats resulting in a comprehensive series of physiological hemodynamic data comparable to single data reported from other groups7. Therefore we considered this procedure to represent a good basis for adapting it to the mouse, a species 10-fold smaller than the rat. The key difference to the rat procedure is the use of Millar catheters for acquiring blood pressure data instead of a fluid-based catheter system. Flow data were also acquired with transonic flow probes, just much smaller ones than for the corresponding rat vessels.
Due to the small size of the animal, instrumentation of mice is technically challenging, but feasible. Once instrumentation is completed, data acquisition and primary life data analysis is simple, since a predefined setting file can be used. The setting file has to be defined once at the beginning of a series of experiments and can be stored and used for all subsequent experiments.
Up to now we applied this procedure to assess hepatic hemodynamic effects in acute experiments. We measured CAP and PVP before and immediately after 70% partial hepatectomy (PH) and in clamping/de-clamping experiments. We clamped the hepato-duodenal ligament of the right lobe representing 20% of the liver mass followed by brief (5min) clamping of the median and left lateral lobe representing totally 90% of the liver mass. De-clamping started with releasing the clamp from the right lobe followed by freeing the median and left lateral lobe. Maximal clamping time was below 10 min.

<table border="0" cellpadding="0" cellspacing="0" width="606">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:104px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">PowerLab 16/30&#160;</td>
			<td style="width:104px;">ADInstruments</td>
			<td>PL3516</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Quad Bridge Amp</td>
			<td style="width:104px;">ADInstruments</td>
			<td>&#160;FE224</td>
			<td>Bridge amplifier&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Animal Bio Amp</td>
			<td style="width:104px;">ADInstruments</td>
			<td>&#160;FE136</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Needle Electrodes for FE136 (3 pk)</td>
			<td style="width:104px;">ADInstruments</td>
			<td>&#160;MLA1213</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Perivascular Flowmeter Module</td>
			<td style="width:104px;">Transonic</td>
			<td style="width:119px;">TS420&#160;</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Flowprobe MA0.5PSB/MA1PSB</td>
			<td style="width:104px;">Transonic</td>
			<td style="width:119px;">MA0.5PSB/MA1PSB</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">SPR-1000 Mouse Pressure Catheter</td>
			<td style="width:104px;">Millar instruments</td>
			<td>841-0001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">fluid filled catheter&#160;</td>
			<td>Terumo</td>
			<td style="width:119px;">SR+DU2619PX</td>
			<td>26G, 0.64&#215;19mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;"></td>
			<td></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">micro scissors</td>
			<td>F&#183;S&#183;L</td>
			<td>No. 14058-09</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">micro serrefine</td>
			<td>F&#183;S&#183;L</td>
			<td>No.18055-05</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Micro clamps applicator</td>
			<td style="width:104px;">F&#183;S&#183;L</td>
			<td style="width:119px;">No. 18057-14</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Straight micro forceps</td>
			<td style="width:104px;">F&#183;S&#183;L</td>
			<td style="width:119px;">No. 00632-11</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Curved micro forceps</td>
			<td style="width:104px;">F&#183;S&#183;L</td>
			<td style="width:119px;">No. 00649-11</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">needle-holder</td>
			<td style="width:104px;">F&#183;S&#183;L</td>
			<td style="width:119px;">No. 12061-01</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;"></td>
			<td style="width:104px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">6-0 silk</td>
			<td style="width:104px;">ethicon</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">6-0 prolene</td>
			<td style="width:104px;">ethicon</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">7-0 prolene</td>
			<td style="width:104px;">ethicon</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">10-0 prolene</td>
			<td style="width:104px;">ethicon</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Tail cut-off device&#160;</td>
			<td style="width:104px;">Kent Scientific</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">www.kentscientific.com</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">LabChart7</td>
			<td style="width:104px;">ADInstruments</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">data&#160; analysis software&#160;</td>
		</tr>
	</tbody>
</table>

monitoring of systemic and hepatic hemodynamic parameters in mice

The use of mouse models in experimental research is of enormous importance for the study of hepatic physiology and pathophysiological disturbances. However, due to the small size of the mouse, technical details of the intraoperative monitoring procedure suitable for the mouse were rarely described. Previously we have reported a monitoring procedure to obtain hemodynamic parameters for rats. Now, we adapted the procedure to acquire systemic and hepatic hemodynamic parameters in mice, a species ten-fold smaller than rats. This film demonstrates the instrumentation of the animals as well as the data acquisition process needed to assess systemic and hepatic hemodynamics in mice. Vital parameters, including body temperature, respiratory&#160;rate&#160;and heart&#160;rate were recorded throughout the whole procedure. Systemic hemodynamic parameters consist of carotid artery pressure (CAP) and central venous pressure (CVP). Hepatic perfusion parameters include portal vein pressure (PVP), portal flow rate as well as the flow rate of the common hepatic artery (table 1). Instrumentation and data acquisition to record the normal values was completed within 1.5 h. Systemic and hepatic hemodynamic parameters remained within normal ranges during this procedure.
This procedure is challenging but feasible. We have already applied this procedure to assess hepatic hemodynamics in normal mice as well as during 70% partial hepatectomy and in liver lobe clamping experiments. Mean PVP after resection (n= 20), was 11.41&#177;2.94 cmH2O which was significantly higher (P&#60;0.05) than before resection (6.87&#177;2.39 cmH2O). The results of liver lobe clamping experiment indicated that this monitoring procedure is sensitive and suitable for detecting small changes in portal pressure and portal flow rate. In conclusion, this procedure is reliable in the hands of an experienced micro-surgeon but should be limited to experiments where mice are absolutely needed.

Vital parameters of the mice such as respiratory rate and heart rate are obviously much higher than in rat. Mean systemic blood pressure and jugular vein pressure are similar to rat values and even similar to the human data.
Hepatic hemodynamic data are obviously different. We obtained normal values from 8 mice. Portal blood flow in normal mice ranged between 1.6 to 2.3 ml/min. Flow in the common hepatic artery ranged from 0.10 to 0.35 ml/min. Portal vein pressure in normal animals was in the ...

Watch this Scientific Journal Video about Monitoring of Systemic and Hepatic Hemodynamic Parameters in Mice at JoVE.com

Monitoring of Systemic and Hepatic Hemodynamic Parameters in Mice

This film demonstrates how to acquire systemic and hepatic hemodynamics in mice. The whole monitoring includes acquisition of vital parameters, systemic blood pressure, central venous pressure, common hepatic artery flow rate, and portal vein pressure as well as the portal flow rate in mice.

The use of mouse models in experimental research is of enormous importance for the study of hepatic physiology and pathophysiological disturbances. ...

monitoring-of-systemic-and-hepatic-hemodynamic-parameters-in-mice

Universidad de Cartagena UDEC

Research

JoVE Journal

Medicine

16.0K Views.  Jena University Hospital. This film demonstrates how to acquire systemic and hepatic hemodynamics in mice. The whole monitoring includes acquisition of vital parameters, systemic blood pressure, central venous pressure, common hepatic artery flow rate, and portal vein pressure as well as the portal flow rate in mice.

Video: Monitoring of Systemic and Hepatic Hemodynamic Parameters in Mice

Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention

One desirable endpoint of general anesthesia is the state of unconsciousness, also known as hypnosis. Defining the hypnotic state in animals is less straightforward than it is in human patients. A widely used behavioral surrogate for hypnosis in rodents is the loss of righting reflex (LORR), or the point at which the animal no longer responds to their innate instinct to avoid the vulnerability of dorsal recumbency. We have developed a system to assess LORR in 24 mice simultaneously while carefully controlling for potential confounds, including temperature fluctuations and varying gas flows. These chambers permit reliable assessment of anesthetic sensitivity as measured by latency to return of the righting reflex (RORR) following a fixed anesthetic exposure. Alternatively, using stepwise increases (or decreases) in anesthetic concentration, the chambers also enable determination of a population's sensitivity to induction (or emergence) as measured by EC50 and Hill slope. Finally, the controlled environmental chambers described here can be adapted for a variety of alternative uses, including inhaled delivery of other drugs, toxicology studies, and simultaneous real-time monitoring of vital signs.

Loss of the righting reflex has long served as a standard behavioral surrogate for unconsciousness, also called hypnosis, in laboratory animals. Alterations in volatile anesthetic sensitivity caused by pharmacological interventions can be detected with a carefully controlled high-throughput assessment system, which may be adapted for delivery of any inhaled therapeutic.

One desirable endpoint of general anesthesia is  the state of unconsciousness, also known as hypnosis. Defining the hypnotic state in animals is  less ...

Clinical Assessment of Spatiotemporal Gait Parameters in Patients and Older Adults

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and neurological patients1-4, but also in healthy older adults5,6. The quantitative gait analysis described in this protocol is performed with a recently-introduced photoelectric system (see&#160;Materials table) which has the potential to be used in the clinic because it is portable, easy to set up (no subject preparation is required before a test), and does not require maintenance and sensor calibration. The photoelectric system consists of series of high-density floor-based photoelectric cells with light-emitting and light-receiving diodes that are placed parallel to each other to create a corridor, and are oriented perpendicular to the line of progression7. The system simply detects interruptions in light signal, for instance due to the presence of feet within the recording area. Temporal gait parameters and 1D spatial coordinates of consecutive steps are subsequently calculated to provide common gait parameters such as step length, single limb support and walking velocity8, whose validity against a criterion instrument has recently been demonstrated7,9. The measurement procedures are very straightforward; a single patient can be tested in less than 5 min&#160;and a comprehensive report can be generated in less than 1&#160;min.

This protocol is used to evaluate spatial and temporal gait variables of neurological/orthopedic patients and older persons by means of a recently-introduced floor-based photocell system.

Spatial and temporal characteristics of human walking are frequently evaluated to identify possible gait impairments, mainly in orthopedic and ...

Carotid Artery Infusions for Pharmacokinetic and Pharmacodynamic Analysis of Taxanes in Mice

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study model. As the use of mouse models are often a vital step in preclinical drug discovery and drug development1-8, it is necessary to design a system to introduce drugs into mice in a uniform, reproducible manner. Ideally, the system should permit the collection of blood samples at regular intervals over a set time course. The ability to measure drug concentrations by mass-spectrometry, has allowed investigators to follow the changes in plasma drug levels over time in individual mice1, 9, 10. In this study, paclitaxel was introduced into transgenic mice as a continuous arterial infusion over three hours, while blood samples were simultaneously taken by retro-orbital bleeds at set time points. Carotid artery infusions are a potential alternative to jugular vein infusions, when factors such as mammary tumors or other obstructions make jugular infusions impractical. Using this technique, paclitaxel concentrations in plasma and tissue achieved similar levels as compared to jugular infusion. In this tutorial, we will demonstrate how to successfully catheterize the carotid artery by preparing an optimized catheter for the individual mouse model, then show how to insert and secure the catheter into the mouse carotid artery, thread the end of the catheter out through the back of the mouse&#8217;s neck, and hook the mouse to a pump to deliver a controlled rate of drug influx. Multiple low volume retro-orbital bleeds allow for analysis of plasma drug concentrations over time.

This method was developed with the goal of delivering a steady drug solution via the carotid artery, to assess the pharmacokinetics of novel drugs in mouse models.

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study ...

Early Detection of Drug-Induced Renal Hemodynamic Dysfunction Using Sonographic Technology in Rats

The kidney normally functions to maintain hemodynamic homeostasis and is a major site of damage caused by drug toxicity. Drug-induced nephrotoxicity is estimated to contribute to 19- 25% of all clinical cases of acute kidney injury (AKI) in critically ill patients. AKI detection has historically relied on metrics such as serum creatinine (sCr) or blood urea nitrogen (BUN) which are demonstrably inadequate in full assessment of nephrotoxicity in the early phase of renal dysfunction. Currently, there is no robust diagnostic method to accurately detect hemodynamic alteration in the early phase of AKI while such alterations might actually precede the rise in serum biomarker levels. Such early detection can help clinicians make an accurate diagnosis and help in in decision making for therapeutic strategy. Rats were treated with Cisplatin to induce AKI. Nephrotoxicity was assessed for six days using high-frequency sonography, sCr measurement and upon histopathology of kidney. Hemodynamic evaluation using 2D and Color-Doppler images were used to serially study nephrotoxicity in rats, using the sonography. Our data showed successful drug-induced kidney injury in adult rats by histological examination. Color-Doppler based sonographic assessment of AKI indicated that resistive-index (RI) and pulsatile-index (PI) were increased in the treatment group; and peak-systolic velocity (mm/s), end-diastolic velocity (mm/s) and velocity-time integral (VTI, mm) were decreased in renal arteries in the same group. Importantly, these hemodynamic changes evaluated by sonography preceded the rise of sCr levels. Sonography-based indices such as RI or PI can thus be useful predictive markers of declining renal function in rodents. From our sonography-based observations in the kidneys of rats that underwent AKI, we showed that these noninvasive hemodynamic measurements may consider as an accurate, sensitive and robust method in detecting early stage kidney dysfunction. This study also underscores the importance of ethical issues associated with animal use in research.

Early stage hemodynamic dysfunction is critical to the development of kidney disease. Yet, detection methodologies are limited. Recent advances in sonography provide a noninvasive, accurate option for early detection of kidney injury. This study outlines a step-by-step, sonographic methodology for detecting kidney dysfunction using a drug-induced nephrotoxicity rat model.

The kidney normally functions to maintain hemodynamic homeostasis and is a major site of damage caused by drug toxicity. Drug-induced nephrotoxicity is ...

The bm12 Inducible Model of Systemic Lupus Erythematosus (SLE) in C57BL/6 Mice

Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical and immunological manifestations. Several spontaneous and inducible animal models mirror common components of human disease, including the bm12 transfer model. Upon transfer of bm12 splenocytes or purified CD4 T cells, C57BL/6 mice rapidly develop large frequencies of T follicular helper cells (Tfh), germinal center (GC) B cells, and plasma cells followed by high levels of circulating anti-nuclear antibodies. Since this model utilizes mice on a pure C57BL/6 background, researchers can quickly and easily study disease progression in transgenic or knockout mouse strains in a relatively short period of time. Here we describe protocols for the induction of the model and the quantitation Tfh, GC B cells, and plasma cells by multi-color flow cytometry. Importantly, these protocols can also be used to characterize disease in most mouse models of SLE and identify Tfh, GC B cells, and plasma cells in other disease models.

The bm12 Inducible Model of Systemic Lupus Erythematosus SLE in C57BL/6 Mice

The transfer of bm12 lymphocytes into a C57BL/6 recipient is an established model of systemic lupus erythematosus. Here we describe how to initiate disease using this model and how to characterize T follicular helper cells, germinal center B cells and plasma cells by flow cytometry.

Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical and immunological manifestations. Several spontaneous and inducible ...

Optimized Analysis of In Vivo and In Vitro Hepatic Steatosis

Establishing a system of procedures to qualitatively and quantitatively characterize in vivo and in vitro hepatic steatosis is important for metabolic study in the liver. Here, numerous assays are described to comprehensively measure the phenotype and parameters of hepatic steatosis in mouse and hepatocyte models. 
Combining the physiological, histological, and biochemical methods, this system can be used to assess the progress of hepatic steatosis. In vivo, the measurements of body weight and nuclear magnetic resonance (NMR) provide a general understanding of mice in a non-invasive manner. Hematoxylin and Eosin (H&amp;E) and Oil Red O staining determine the histological morphology and lipid deposition of liver tissue under nutrient overload conditions, such as high-fat diet feeding. Next, the total lipid contents are isolated by chloroform/methanol extraction, which are followed by a biochemical analysis for triglyceride and cholesterol. Moreover, mouse primary hepatocytes are treated with high glucose plus insulin to stimulate lipid accumulation, an efficient in vitro model to mimic diet-induced hyperglycemia and hyperinsulinemia in vivo. Then, the lipid deposition is measured by Oil Red O staining and chloroform/methanol extraction. Oil Red O staining determines intuitive hepatic steatotic phenotypes, while the lipid extraction analysis determines the parameters that can be analyzed statistically. The present protocols are of interest to scientists in the fields of fatty liver diseases, insulin resistance, and type 2 diabetes.

Optimized Analysis of In Vivo and In Vitro Hepatic Steatosis

Here, optimized methods to generate in vivo and in vitro models of hepatic steatosis and to analyze the steatotic phenotypes and related physiological parameters are described.

Establishing a system of procedures to qualitatively and quantitatively characterize in vivo and in vitro hepatic steatosis is important for metabolic ...

Uncontrolled Hemorrhagic Shock Modeled via Liver Laceration in Mice with Real Time Hemodynamic Monitoring

Uncontrolled hemorrhage is an important cause of preventable deaths among trauma patients. We have developed a murine model of uncontrolled hemorrhage via a liver laceration that results in consistent blood loss, hemodynamic alterations, and survival.
Mice undergo a standardized resection of the left-middle lobe of the liver. They are allowed to bleed without mechanical intervention. Hemostatic agents can be administered as pre-treatment or rescue therapy depending on the interest of the investigator. During the time of hemorrhage, real-time hemodynamic monitoring via a left femoral arterial line is performed. Mice are then sacrificed, blood loss is quantified, blood is collected for further analysis, and organs are harvested for analysis of injury. Experimental design is described to allow for simultaneous testing of multiple animals.
Liver hemorrhage as a model of uncontrolled hemorrhage exists in the literature, primarily in rat and porcine models. Some of these models utilize hemodynamic monitoring or quantify blood loss but lack consistency. The present model incorporates quantification of blood loss, real-time hemodynamic monitoring in a murine model that offers the advantage of using transgenic lines and a high-throughput mechanism to further investigate the pathophysiologic mechanisms in uncontrolled hemorrhage.

Uncontrolled hemorrhage, an important cause of mortality among trauma patients, can be modeled using a standard liver laceration in a murine model. This model results in consistent blood loss, survival, and allows for testing hemostatic agents. This article provides the step-by-step process to perform this valuable model.

Uncontrolled hemorrhage is an important cause of preventable deaths among trauma patients. We have developed a murine model of uncontrolled hemorrhage via ...

A Detailed Protocol for Physiological Parameters Acquisition and Analysis in Neurosurgical Critical Patients

Intracranial pressure (ICP) monitoring is now widely used in neurosurgical critical patients. Besides mean ICP value, the ICP derived parameters such as ICP waveform, amplitude of pulse (AMP), the correlation of ICP amplitude and ICP mean (RAP), pressure reactivity index (PRx), ICP and arterial blood pressure (ABP) wave amplitude correlation (IAAC), and so on, can reflect intracranial status, predict prognosis, and can also be used as guidance of proper treatment. However, most of the clinicians focus only on the mean ICP value while ignoring these parameters because of the limitations of the current devices. We have recently developed a multimodality monitoring system to address these drawbacks. This portable, user-friendly system will use a data collecting and storing device to continuously acquire patients&#39; physiological parameters first, i.e., ABP, ICP, and oxygen saturation, and then analyze these physiological parameters. We hope that the multimodality monitoring system will be accepted as a key measure to monitor physiological parameters, to analyze the current clinical status, and to predict the prognosis of the neurosurgical critical patients.

Recently, we have developed a portable multimodality monitoring system for the monitoring of various physiological parameters in neurosurgical critical patients. Detailed protocols on how to use this multimodality monitoring system are presented here.

Intracranial pressure (ICP) monitoring is now widely used in neurosurgical critical patients. Besides mean ICP value, the ICP derived parameters such as ...

The Pilocarpine Model of Temporal Lobe Epilepsy and EEG Monitoring Using Radiotelemetry System in Mice

Temporal lobe epilepsy (TLE) is a common neurological disorder in adulthood. For translational studies of chronic epilepsy, pilocarpine-induced status epilepticus (SE) is frequently selected to recapitulate spontaneous recurrent seizures (SRS). Here we present a protocol of SE induction by intraperitoneal (i.p.) injection of pilocarpine and monitoring of chronic recurring seizures in live animals using a wireless telemetry video and electroencephalogram (EEG) system. We demonstrated notable behavioral changes that need attention after pilocarpine injection and their correlation with hippocampal neuronal loss at 7 days and 6 weeks post-pilocarpine. We also describe the experimental procedures of electrode implantation for video and EEG recording, and analysis of the frequency and duration of chronic recurrent seizures. Finally, we discuss the possible reasons why the expected results are not achieved in each case. This provides a basic overview of modeling chronic epilepsy in mice and guidelines for troubleshooting. We believe this protocol can serve as a baseline for suitable models of chronic epilepsy and epileptogenesis.

This manuscript describes a method of inducing status epilepticus by systemic pilocarpine injection and of monitoring spontaneous recurrent seizures in live animals using a wireless telemetry video and electroencephalogram system. This protocol can be utilized for studying the pathophysiologic mechanisms of chronic epilepsy, epileptogenesis, and acute seizures.

Temporal lobe epilepsy (TLE) is a common neurological disorder in adulthood. For translational studies of chronic epilepsy, pilocarpine-induced status ...

Invasive Hemodynamic Characterization of the Portal-hypertensive Syndrome in Cirrhotic Rats

This is a detailed protocol describing invasive hemodynamic measurements in cirrhotic rats for the characterization of portal hypertensive syndrome. Portal hypertension (PHT) due to cirrhosis is responsible for the most severe complications in patients with liver disease. The full picture of the portal hypertensive syndrome is characterized by increased portal pressure (PP) due to the increased intrahepatic vascular resistance (IHVR), hyperdynamic circulation, and increased splanchnic blood flow. Progressive splanchnic arterial vasodilation and increased cardiac output with elevated heart rate (HR) but low arterial pressure characterizes the portal hypertensive syndrome.
Novel therapies are currently being developed that aim to decrease PP by either targeting IHVR or increased splanchnic blood flow &#8212; but side effects on systemic hemodynamics may occur. Thus, a detailed characterization of portal venous, splanchnic, and systemic hemodynamic parameters, including measurement of PP, portal venous blood flow (PVBF), mesenteric arterial blood flow, mean arterial pressure (MAP), and HR is needed for preclinical evaluation of the efficacy of novel treatments for PHT. Our video article provides the reader with a structured protocol for performing invasive hemodynamic measurements in cirrhotic rats. In particular, we describe the catheterization of the femoral artery and the portal vein via an ileocolic vein and the measurement of portal venous and splanchnic blood flow via perivascular Doppler-ultrasound flow probes. Representative results of different rat models of PHT are shown.

Here we describe a detailed protocol for invasive measurements of hemodynamic parameters including portal pressure, splanchnic blood flow, and systemic hemodynamics in order to characterize the portal hypertensive syndrome in rats.

This is a detailed protocol describing invasive hemodynamic measurements in cirrhotic rats for the characterization of portal hypertensive syndrome. ...

Monitoring of Systemic and Hepatic Hemodynamic Parameters in Mice

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Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention

Clinical Assessment of Spatiotemporal Gait Parameters in Patients and Older Adults

Carotid Artery Infusions for Pharmacokinetic and Pharmacodynamic Analysis of Taxanes in Mice

Early Detection of Drug-Induced Renal Hemodynamic Dysfunction Using Sonographic Technology in Rats

The bm12 Inducible Model of Systemic Lupus Erythematosus (SLE) in C57BL/6 Mice

Optimized Analysis of In Vivo and In Vitro Hepatic Steatosis

Uncontrolled Hemorrhagic Shock Modeled via Liver Laceration in Mice with Real Time Hemodynamic Monitoring

A Detailed Protocol for Physiological Parameters Acquisition and Analysis in Neurosurgical Critical Patients

The Pilocarpine Model of Temporal Lobe Epilepsy and EEG Monitoring Using Radiotelemetry System in Mice

Invasive Hemodynamic Characterization of the Portal-hypertensive Syndrome in Cirrhotic Rats