The Influence on Neural Conduction after Alcohol Injection into Penile Dorsal Nerve of Rats

Lee, Sang Jae; Seo, Ill Young; Rim, Hee Kwan; Kim, Jae Hyo; Han, Weon Cheol; Rim, Joung Sik

Abstract

PURPOSE
Premature ejaculation is the most common male sexual disorder, affecting perhaps as many as 75% of men, but its cause has not been well established. The objective of this study is to evaluate whether alcohol injection on the dorsal aspect of the penis can induce a desensitization of penile sensory nerve fiber in rats.
MATERIALS AND METHODS
Forty-four male Sprague-Dawley rats were divided into 4 groups. Group I of 4 rats, the control group, did not undergo any procedure. Group II of 8 rats, received only an alcohol injection without electrical stimulation. In group III of 4 rats, only electrical stimulation was performed without alcohol injection. In group IV of 28 rats, all rats received an alcohol injection on the dorsal aspect of the penis, and groups of four rats were sacrificed after electrical stimulation on the glans penis at 1, 2, 4, 7, 10, 14, and 21 days after alcohol injection. Spinal cords were sectioned and processed for immunohistochemical staining for c-Fos protein.
RESULTS
No c-Fos protein was detected in the normal control group, and either none or few c-Fos protein positive neurons were seen in the alcohol injection only group. The number of c-Fos protein positive neurons in the electrical stimulation only group was 30.25+/-3.53 cells/section. Four days after alcohol injection, the level of c-Fos protein positive neurons was reduced significantly compared with the control group (p<0.05), and was very close to the control group at 10 days after alcohol injection.
CONCLUSIONS
Our study demonstrates that alcohol injection in the dorsal aspect of the penis reduces c-Fos protein positive neurons in the spinal cord segment through desensitization of penile sensory nerve fibers.