Name: long-term blood pressure measurement in freely moving mice using telemetry
Uploaded: 2016-05-17T14:00:00
Description: Watch this Scientific Journal Video about Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry at JoVE.com

This work was supported by the National Institutes of Health (NIH/NHLBI) [Grant no. HL114869] and the support from UTHSC to SM.

Ethics statement: All animal procedures mentioned in this video-article were reviewed and approved by the Animal Care and Use Committee (IACUC)&#160;at the University of Tennessee Health Science Center.
Note: Use sterile microsurgery instruments throughout the surgical procedure. Surgical instruments may be sterilized utilizing an infrared sterilizer at an optimum sterilizing temperature of 1,500 &#176;F (815.6&#160;&#176;C). Telemeters can be reused, however, before inserting it in the animal make sure to sterilize the entire transmi...

<ol>
	<li>Danaei, 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=The+preventable+causes+of+death+in+the+United+States:+comparative+risk+assessment+of+dietary,+lifestyle,+and+metabolic+risk+factors.">The preventable causes of death in the United States: comparative risk assessment of dietary, lifestyle, and metabolic risk factors.</a> PLoS Med. 6 (4), e1000058 (2009).</li><li>Dornas, W. C., Silva, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+for+the+study+of+arterial+hypertension.">Animal models for the study of arterial hypertension.</a> J Biosci. 36 (4), 731-737 (2011).</li><li>Henze, 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=Persistent+alterations+in+heart+rate+variability,+baroreflex+sensitivity,+and+anxiety-like+behaviors+during+development+of+heart+failure+in+the+rat.">Persistent alterations in heart rate variability, baroreflex sensitivity, and anxiety-like behaviors during development of heart failure in the rat.</a> Am J Physiol Heart Circ Physiol. 295 (1), H29-H38 (2008).</li><li>Hoffmann, D. S., 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=Chronic+tempol+prevents+hypertension,+proteinuria,+and+poor+feto-placental+outcomes+in+BPH/5+mouse+model+of+preeclampsia.">Chronic tempol prevents hypertension, proteinuria, and poor feto-placental outcomes in BPH/5 mouse model of preeclampsia.</a> Hypertension. 51 (4), 1058-1065 (2008).</li><li>Lerman, L. O., Chade, A. R., Sica, V., Napoli, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+hypertension:+an+overview.">Animal models of hypertension: an overview.</a> J Lab Clin Med. 146 (3), 160-173 (2005).</li><li>Johns, C., Gavras, I., Handy, D. E., Salomao, A., Gavras, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Models+of+experimental+hypertension+in+mice.">Models of experimental hypertension in mice.</a> Hypertension. 28 (6), 1064-1069 (1996).</li><li>Vatner, S. F., Braunwald, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiovascular+control+mechanisms+in+the+conscious+state.">Cardiovascular control mechanisms in the conscious state.</a> N Engl J Med. 293 (19), 970-976 (1975).</li><li>Zhao, X., 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=Arterial+Pressure+Monitoring+in+Mice.">Arterial Pressure Monitoring in Mice.</a> Curr Protoc Mouse Biol. 1, 105-122 (2011).</li><li>Whitesall, S. E., Hoff, J. B., Vollmer, A. P., D'Alecy, L. G. <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+simultaneous+measurement+of+mouse+systolic+arterial+blood+pressure+by+radiotelemetry+and+tail-cuff+methods.">Comparison of simultaneous measurement of mouse systolic arterial blood pressure by radiotelemetry and tail-cuff methods.</a> Am J Physiol Heart Circ Physiol. 286 (6), H2408-H2415 (2004).</li><li>Kurtz, T. 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=Recommendations+for+blood+pressure+measurement+in+humans+and+experimental+animals.+Part+2:+Blood+pressure+measurement+in+experimental+animals:+a+statement+for+professionals+from+the+subcommittee+of+professional+and+public+education+of+the+American+Heart+Association+council+on+high+blood+pressure+research.">Recommendations for blood pressure measurement in humans and experimental animals. Part 2: Blood pressure measurement in experimental animals: a statement for professionals from the subcommittee of professional and public education of the American Heart Association council on high blood pressure research.</a> Hypertension. 45 (2), 299-310 (2005).</li><li>Kurtz, T. 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=Recommendations+for+blood+pressure+measurement+in+animals:+summary+of+an+AHA+scientific+statement+from+the+Council+on+High+Blood+Pressure+Research,+Professional+and+Public+Education+Subcommittee.">Recommendations for blood pressure measurement in animals: summary of an AHA scientific statement from the Council on High Blood Pressure Research, Professional and Public Education Subcommittee.</a> Arterioscler Thromb Vasc Biol. 25 (3), 478-479 (2005).</li></ol>

Implantable radio-telemetry has improved significantly over the last decade; smaller probe size makes the implant less traumatic for the animal, prolonged battery life helps to reduce the costs, and independent telemeter frequencies eliminate crosstalk between receivers. Telemetry is considered the state-of-the-art method for collecting a wide variety of physiological parameters from freely moving animals without the artifacts associated with the use of restraint, human interaction, or anesthesia that are required by oth...

Hypertension is one of the major risk factors for cardiovascular diseases, arguably it is a major public health issue both in developed and developing countries1. Several animal models of experimental hypertension have been developed to mimic hypertensive responses like those observed in humans2. Among others, the ambulatory mouse represents an excellent model to study the genesis and the progression of hypertension allowing in&#160;vivo analysis of the consequences of chronic exposure to hypertension.
Blood pressure (BP) monitoring in mice has helped researchers to unravel several mechanisms involved in the physiology and pathophysiology of diseases such as hypertension and heart failure3,4. Indeed, manipulation of the mouse genome allowed generation of transgenic or gene-targeted models suitable for studying hypertension5,6. However, even gentle manipulation of conscious mice induces excitements that can potentially introduce artifacts during data acquisition, while use of sedation or tranquilizers profoundly affect blood pressure7. These aspects are particularly important and must be taken in consideration when attempting long-term BP monitoring.
There are several ways to record BP in mice, and a comparison between the most common techniques currently available has been discussed elsewhere8,9. However, the AHA recommendations for BP measurement concluded that intra-arterial measurement of BP are generally preferred because of their ability to directly measure BP over an extended period of time10. Radio-telemetry coupled with direct measurement of arterial pressure is the state-of-the-art method for monitoring physiological functions in awake and freely moving laboratory animals while minimizing stress and environmentally-associated artifacts9,11. Radio-telemetry offers the ability to automatically collect blood pressures, heart rate, body temperature and animal activity from multiple conscious animals.
Although this methodology is becoming very popular in many laboratories, radio-telemetry implantation in mice can be technically challenging. Here we show a step-by-step protocol that illustrates how to implant a pressure transducer in mice. The technique involves subcutaneous insertion of the probe in the mouse body, channel the catheter to the neck and forward near the aortic arch via the left carotid artery. Remotely captured data are shown live on the computer monitor.&#160;Data are also stored for &#34;off-line&#34; analysis.

<table>
	<tbody>
		<tr>
			<td>Small animal anesthesia system</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td></td>
			<td>low-Flow small animal anesthesia system</td>
		</tr>
		<tr>
			<td>Pad warmer and mouse termometer</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td></td>
			<td>allows monitoring body temperature,&#160; and homeothermic control in small animals.</td>
		</tr>
		<tr>
			<td>Binocular Microscope</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td>KSCXTS-1121</td>
			<td>binocular body with boom stand pole and top LED.</td>
		</tr>
		<tr>
			<td>Hemostat Forceps</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td>INS750451</td>
			<td>used to clamp blood vessels or tag sutures</td>
		</tr>
		<tr>
			<td>Small metal Clips, 7mm, Stainless Steel</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td>INS750344</td>
			<td>used for skin closure</td>
		</tr>
		<tr>
			<td>Betadine solution</td>
			<td>Purdue Products L.P., Stamford, CT, USA</td>
			<td>NDC-67618-150-01</td>
			<td>10% povidone iodine topical solution</td>
		</tr>
		<tr>
			<td>Normal saline solution</td>
			<td>Abott Laboratories</td>
			<td>04930-04-10</td>
			<td>Needed for preventing tissue from drying.</td>
		</tr>
		<tr>
			<td>Nair (Hair remover lotion)</td>
			<td></td>
			<td></td>
			<td>Needed for fur removal from the site of incision/surgery.</td>
		</tr>
		<tr>
			<td>Braide silk suture</td>
			<td>Teleflex Medical OEM, Coventry, Connecticut, USA</td>
			<td></td>
			<td>Size 5.0, 6.0, 7.0</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td></td>
			<td>2716</td>
			<td>70% ethanol for disinfection</td>
		</tr>
		<tr>
			<td>Spring scissors&#160;</td>
			<td>Fine Science Tool</td>
			<td>15000-10</td>
			<td>for minor dissection</td>
		</tr>
		<tr>
			<td>Scissors (angled to side)</td>
			<td>Fine Science Tool</td>
			<td>14063-011</td>
			<td>No. 3 handle</td>
		</tr>
		<tr>
			<td>Scalpel blade</td>
			<td></td>
			<td>2976-0</td>
			<td>No. 10</td>
		</tr>
		<tr>
			<td>Forceps (curved)</td>
			<td>Fine Science Tool</td>
			<td>11150-10</td>
			<td>for holding tissue</td>
		</tr>
		<tr>
			<td>Forceps (straight)</td>
			<td>Fine Science Tool</td>
			<td>11151-10</td>
			<td>for holding tissue</td>
		</tr>
		<tr>
			<td>Needle holder&#160;</td>
			<td>Fine Science Tool</td>
			<td>12002-12</td>
			<td>for suturing</td>
		</tr>
		<tr>
			<td>Fine needle nose Forceps</td>
			<td>Fine Science Tool</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Henry Schein&#160;Animal Health, Melville, New York, USA</td>
			<td></td>
			<td>a general inhalation anesthetic agent</td>
		</tr>
		<tr>
			<td>Sterilizer</td>
			<td>Benchmark Scientific, 116 Corporate Blvd, South Plainfield, NJ, USA</td>
			<td>B1000</td>
			<td>sterilize surgical tools&#160;in 5-10 seconds using infrared heating</td>
		</tr>
		<tr>
			<td>Gauze Pads</td>
			<td>Johnson &#38; Johnson, New Brunswick, NJ, USA</td>
			<td>JJ8513</td>
			<td>to use for wound cleaning, prepping, scrubbin or dressing.</td>
		</tr>
		<tr>
			<td>Telemetry Device</td>
			<td>Data Sciences International, St. Paul, MN, USA</td>
			<td>DSI-PA-C10</td>
			<td>to record blood pressure in freely moving mice</td>
		</tr>
		<tr>
			<td>Telemetry receiver system&#160; coumpled with a PC</td>
			<td>Data Sciences International, St. Paul, MN, USA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>small Tubing</td>
			<td>Instech Laboratories, Plymouth Meeting, PA USA</td>
			<td>BTPE-90</td>
			<td></td>
		</tr>
		<tr>
			<td>Vessel Cannulation Forceps, 13cm, 0.5mm OD</td>
			<td>World Precision Instruments</td>
			<td>503374</td>
			<td>special vessel cannulation forceps.</td>
		</tr>
		<tr>
			<td>Tissue adhesive</td>
			<td>3M Animal Care Products, St. Paul, MN, USA</td>
			<td>NAC No.:&#160;11380041</td>
			<td>&#160;use to close minor wounds, often eliminating the need for sutures and/or bandages</td>
		</tr>
		<tr>
			<td>Weighing scale&#160;</td>
			<td></td>
			<td>BB300</td>
			<td>&#160;Precision Analytical Laboratory Balance</td>
		</tr>
	</tbody>
</table>

long-term blood pressure measurement in freely moving mice using telemetry

During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. Indeed, research focusing on the discovery of new potential therapeutic targets using genetically altered mice requires a reliable, long-term assessment of the systemic arterial pressure variation. Currently, the gold standard for obtaining long-term measurements of blood pressure in ambulatory mice uses implantable radio-transmitters, which require&#160;artery cannulation. This technique eliminates the need for tethering, restraining, or anesthetizing the animals which introduce stress and artifacts during data sampling. However, arterial blood pressure monitoring in mice via catheterization can be rather challenging due to the small size of the arteries. Here we present a step-by-step guide to illustrate the crucial key passages for a successful subcutaneous implantation of radio-transmitters and carotid artery cannulation in mice. We also include examples of long-term blood pressure activity taken from freely moving mice after a period of post-surgery recovery. Following this procedure will allow reliable direct blood pressure recordings from multiple animals simultaneously.

Data can be acquired remotely by a receiver; traces are visualized on a computer screen for quality control (Figure 1a). Details such as animal ID, diastolic blood pressure and&#160;systolic blood pressure&#160;are also shown (Figure 1b). Arterial BP can be recorded continuously (24/7), or for short programmed intervals (i.e., 60 sec&#160;acquisition every hour).&#160;Data can be automatically stored in a hard disk for later analysis. Averaged BP...

Watch this Scientific Journal Video about Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry at JoVE.com

Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry

The goal of this protocol is to assess systemic blood pressure in conscious freely moving mice using implantable radio-telemetry devices.

During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. ...

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