Name: intracavernosal pressure recording to evaluate erectile function in rodents
Uploaded: 2018-06-06T12:30:00
Description: Watch this Scientific Journal Video about Intracavernosal Pressure Recording to Evaluate Erectile Function in Rodents at JoVE.com

This work was supported by the Fundamental Research Funds for the Central Universities (020814380018, 020814380077), The China Scholarship Council (CSC, No. 201606195024), Natural Science Foundation of Jiangsu Province (BK20160138), and Key Project supported by Science and Technology Development Foundation, Nanjing Medical University (2014NJMUZD053).

Three-month-old and 18-month-old Sprague-Dawley rats were used in the present study. All animals were handled in accordance with the NIH Guidelines for the Care and Use of Laboratory Animals. Procedures involving animal subjects were approved by the local Institutional Animal Care and Ethics Committee, with an effort to minimize animal suffering. The protocols were approved by the Institutional Animal Care and Use Committee (IACUC) at Nanjing Tech University (Nanjing, China).
The rats were div...

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As a direct measure of erectile function, ICP is a reliable method14. It allows for the acquisition of data on basal ICP, peak ICP, plateau ICP, time to erection and detumescence time, duration of response, etc. Besides these direct measured parameters, there are some other index parameters: (1) &#34;T80&#34;, the time to reach 80% of peak ICP; (2) &#34;D20&#34;, the time to decrease to 20% of peak ICP; (3) &#34;&#916;T80&#34;, the rate of increase in pressure (per second) at T80; and (4)...

ED is defined as the inability to attain or keep a penile erection, and has become a common male sexual disorder1. Experimental animals are used and provide reproducible models to investigate erectile function2. For a long time, several larger animal models have been employed for investigating erectile function3,4,5. Although rodents are relatively small compared to other animals, they are also used for the study of male erectile dysfunction due to exhibiting several advantages6. First, the morphological and functional sexual characteristics of humans are recapitulated in rodents. Second, compared to larger animals used in ED studies, rodents are more economical to purchase, house, and maintain. Third, genetically modified rodent models provide advantages in reproducible and subsequent behavioral as well as neurophysiological studies. Therefore, rodents have quickly become the primary animals used in the study of male erectile dysfunction.
Benefiting from a pure genetic background and consistent culture conditions, rodent models have provided consistently reproducible data5,6,7,8. Among the numerous available studies related to many aspects of erectile functions, the apomorphine (APO)-induced erectile response test and the electric-stimulation-induced ICP response test are the most widely used methods that reliably reflect erectile function9,10,11,12. The APO-induced erectile function test, developed by Heaton et al.13, is a bio-assay that utilizes the phenomenon that administration of apomorphine to rats elicits erections and yawns. As an easy, noninvasive, and stable bio-assay to evaluate erectile function, the APO-induced erectile function test is widely used in many studies. However, this assay does not adequately reflect the quality of erections or the dynamic changes in blood flow associated with an erectile response14. ICP measurements were initially developed by Quinlan et al.15. In this method, a catheter is placed into the carotid artery to measure systemic blood pressure, and another catheter is inserted into the crus corpus cavernosum to record the ICP. Before or during the ICP recording, a vasoactive agent and/or electrical field stimulation of the major pelvic ganglion (MPG) or CN were often given to the rats14. This assay has been a reliable tool for evaluating the therapies and medicines for ED, and will likely be used as a vital evaluation method in the future6.
Compared to the easily-performed APO-induced erectile function test, successful ICP recordings require attention to detail, practice, and adherence to the operation method. Therefore, here, we provide a detailed description of how to perform ICP recording.

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	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:128px;">Animal</td>
			<td style="width:289px;"></td>
			<td style="width:336px;"></td>
			<td style="width:345px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rats</td>
			<td></td>
			<td></td>
			<td>Strain: Sprague-Dawley 
			Age: 2-3 month</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Rats</td>
			<td></td>
			<td></td>
			<td>Strain: Sprague-Dawley 
			Age: 15-18 month</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Reagents</td>
			<td></td>
			<td></td>
			<td>formula</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:128px;">Saline</td>
			<td style="width:289px;">Sigma-Aldrich, S7653</td>
			<td style="width:336px;"></td>
			<td style="width:345px;">dissolve 8.5 gram sodium chloride in distilled water</td>
		</tr>
		<tr height="68">
			<td height="68" style="height:68px;width:128px;">Pentobarbital sodium solution</td>
			<td style="width:289px;">Sigma-Aldrich, P3761</td>
			<td style="width:336px;"></td>
			<td style="width:345px;">dissolve 1 gram in 100 ml saline</td>
		</tr>
		<tr height="36">
			<td height="36" style="height:36px;width:128px;">Povidone-iodine</td>
			<td>BTP Pharmaceutical Co. Limited</td>
			<td></td>
			<td style="width:345px;">10% (V/V)</td>
		</tr>
		<tr height="36">
			<td height="36" style="height:36px;width:128px;">Ethanol</td>
			<td style="width:289px;">China National Pharmaceutical Group Corporation (SINOPHARM)</td>
			<td style="width:336px;"></td>
			<td style="width:345px;">70% (V/V)</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:128px;">Heparin</td>
			<td style="width:289px;">Sigma-Aldrich, H3149</td>
			<td style="width:336px;"></td>
			<td style="width:345px;">dissolve 20000U heparin in 100 ml saline</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Materials</td>
			<td></td>
			<td colspan="2"></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:128px;">Hypodermic needle</td>
			<td style="width:289px;">Shandong Weigao Group Medical Polymer Co., Ltd.&#160;</td>
			<td>23G</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:128px;">Syringe</td>
			<td style="width:289px;">Shandong Weigao Group Medical Polymer Co., Ltd</td>
			<td>10 ml</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:128px;">Three-way stopcock</td>
			<td style="width:289px;">Chengdu Instrument factory</td>
			<td>TSK 01</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:128px;">Electrode</td>
			<td style="width:289px;">Chengdu Instrument factory</td>
			<td>JST-1</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:128px;">Catheter tube</td>
			<td style="width:289px;">Chengdu Instrument factory</td>
			<td>PE-10, PE-50</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:128px;">Operating scissors</td>
			<td>Shanghai operation equipment factory</td>
			<td>J22010, J22020</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:128px;">Ophthalmic operating scissors</td>
			<td>Shanghai operation equipment factory</td>
			<td>Y00010, Y00020</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:128px;">Ophthalmic forceps</td>
			<td>Shanghai operation equipment factory</td>
			<td>JD1010, JD1020</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:128px;">MicroScissors</td>
			<td>World Precision Instruments</td>
			<td>WAA260</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;width:128px;">silk suture</td>
			<td style="width:289px;">Shandong Weigao Group Medical Polymer Co., Ltd.&#160;</td>
			<td>5-0</td>
			<td></td>
		</tr>
		<tr height="35">
			<td height="35" style="height:35px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Equipment</td>
			<td></td>
			<td colspan="2"></td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:128px;">Stimulator</td>
			<td style="width:289px;">Nanjing medease science and technology co. ltd (model 4C501H)</td>
			<td style="width:336px;"></td>
			<td style="width:345px;">15 Hz, 5 ms pulse, 5 V, 60 s duration and 5 minutes interval</td>
		</tr>
		<tr height="52">
			<td height="52" style="height:52px;width:128px;">Multichannel signal collection processing system</td>
			<td style="width:289px;">Nanjing medease science and technology co. ltd (model 4C501H)</td>
			<td style="width:336px;"></td>
			<td>Blood pressure model</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:128px;">Pressure transducer</td>
			<td style="width:289px;">Beijing Xin Hang Xing Ye Technology Trading Company Limited (model YP100)</td>
			<td style="width:336px;"></td>
			<td>40KPa</td>
		</tr>
	</tbody>
</table>

intracavernosal pressure recording to evaluate erectile function in rodents

Erectile dysfunction (ED) is defined as the inability to attain or keep an erection of the penis, and this has become a prevalent male sexual disorder. Rodents are employed by many studies to research the physiology/pathology of erectile function. Erectile function in rodents can be evaluated by measuring the intracavernosal pressure (ICP). In practice, ICP can be monitored following electrical stimulation of the cavernous nerves (CNs). The arterial pressure of the carotid artery (the mean arterial pressure) is used as the reference for ICP. Using ICP recording protocols, many key parameters of erectile function can be measured from the ICP response curve. The ICP measurement provides more information than the apomorphine-induced penile erection test, and is cheaper than telemetric monitoring of the corpus spongiosum penis, making this method the most popular one to evaluate erectile function. However, compared to the easily-performed APO-induced erectile function test, successful ICP recordings require attention to detail, practice, and adherence to the operation method. In this work, an introduction to ICP recording in rats is provided to complement the procedure efficiently.

Numerous studies have shown that erectile dysfunction in aged males is becoming a common problem. However, medical treatment is limited in the management of aging-related ED16. In rodent models of aging-related ED, many therapies are tested on the erectile function of aged rats. As we have introduced above, the ICP recording test could be used to distinguish the ED animals from the total population of experimental animals, which is also valuable to quantify the eff...

Watch this Scientific Journal Video about Intracavernosal Pressure Recording to Evaluate Erectile Function in Rodents at JoVE.com

Intracavernosal Pressure Recording to Evaluate Erectile Function in Rodents (Video) | JoVE

Intracavernosal pressure recording (ICP) is an important method to evaluate the erectile function of experimental animals. Here, a detailed protocol is demonstrated for the recording procedure of ICP by catheterizing the crura penis and then electrically stimulating the cavernous nerves in rats.

Intracavernosal Pressure Recording to Evaluate Erectile Function in Rodents

Erectile dysfunction (ED) is defined as the inability to attain or keep an erection of the penis, and this has become a prevalent male sexual disorder. ...

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