Intracavernosal pressure monitoring in mice: Responses to electrical stimulation of the cavernous nerve and to intracavernosal drug administration

With the development of transgenic mice to evaluate mechanisms of erectile function, it appears particularly advantageous to develop a standardized mo use model of penile erection. The purpose of the study reported here was to evaluate the novel application of intracavernosal pressure (ICP) monitorin g in the mouse during electrophysiologic and pharmacologic induction of pen ile erection. In anesthetized adult male mice, the cavernous nerves (GN) we re isolated unilaterally, and the corpora cavernosa were exposed. A 24-gaug e angiocath (intravenous catheter) was inserted into the right corpus caver nosum to monitor the ICP, and a 30.5-gauge needle was inserted into the lef t corpus cavernosum for intracavernosal drug administration. ICP was record ed during CN-stimulated or pharmacostimulated erections. Electrical stimula tion of the CN significantly increased the ICP (from 10.09 +/- 2.01 to 34.6 2 +/- 2.71: mm Hg, P < .05), which then returned to baseline pressure after termination of the electrical stimulation. Pretreatment with intracavernos al administration of the nitric oxide synthase inhibitor, nitro-L-arginine methyl ester (0.1 mg), inhibited the electrical stimulation-induced changes in ICP (7.17 +/- 1.46 vs 10.38 +/- 2.17 mm Hg, not significant [NS]). Also , intracavernosal administration of papaverine (0.4 mg) produced a signific ant increase in ICP (from 8.51 +/- 0.69 to 26.37 +/- 5.7 mm Hg, P < .05). W e concluded that this technique might be applied to perform quantitative er ection physiologic experiments with the mouse as an economical and experime ntally advantageous animal model, particularly with the development of tran sgenic mice to evaluate mechanisms of erectile function.