Is Peak Penile Blood Flow Volume Velocity with Electromagnetic Blood Flowmeter Suitable for the Index of Penile Erection Evaluation in a Rat as Intracavernous Pressure?

Song, Yun Seob; Park, Young Ho; Kim, Hyung Gun

Abstract

PURPOSE
The development of a new series drugs for treating erectile dysfunction presents the a need for an easy and inexpensive animal experimental models for evaluating the drug effects on penile erectile function. The intracavernous pressure (ICP) is a suitable index for evaluating a penile erection. However, the continuous monitoring of the changes in the penile blood flow volume with an electromagnetic blood flowmeter may provide a new model for measuring the peak penile blood flow volume velocity (PBFVV) as a new index for a penile erection in a rat.
MATERIALS AND METHODS
To establish a new suitable index for evaluating a penile erection in rats, measuring both the PBFVV with an electromagnetic blood flowmeter and the ICP with a polygraph were performed and compared. Fifty male adult Sprague-Dawley rats (250 gm) were divided into ICP and PBFVV measurement groups. The rats were anesthetized with 50mg/kg of pentobarbital sodium by an intraperitoneal injection. The left carotid artery was cannulated to measure the systemic blood pressure. Saline or papaverine were injected intracavernously. The ICP was measured with a pressure transducer and a polygraph. The PBFVV was measured after the penile shaft was placed in the ring of a electromagnetic blood flowmeter probe.
RESULTS
Both the ICP and peak PBFVV following the intracavernous injection of papaverine were higher compared to both the ICP and peak PBFVV following the saline injection. Both the ICP and PBFVV after an intracavernous papaverine injection increased up to a peak value and then decreased. There was no significant concomitant changes in the systemic blood pressure.
CONCLUSIONS
The PBFVV in rats were higher and reflected the veno-occlusive response following the intracavernous papaverine injection as well as the ICP. It is suggested that the peak PBFVV with the electromagnetic blood flowmeter as well as the ICP represents a suitable index for evaluating a penile erection in a rats.