Effect of Coitus (Copulation) on Sperm Parameters and Gonadosomatic Index in Hemi-orchidectomized Wistar Rats

Background: There are conflicting reports on the effect of coitus on seminal parameters. Similarly, studies believe hemi-orchidectomy improves the function of the contralateral testis while others observed no differences in the function of the contralateral testis. But there is paucity of information on the effect of coitus on seminal parameters in hemi-orchidectomized animals, and hence this study. Methods: Twenty (20) male Wistar rats were used for this study. The 20 male rats were divided into 4 groups of 5 rats each. Group 1 (both testes, no coitus); group 2 (both testes, with coitus); group 3 (hemi-orchidectomized, no coitus) and group 4 (hemi-orchidectomized, with coitus). Each male rat in groups 2 and 4 was cohabited with 2 females for three months after two weeks of the orchidectomy. Animals were sacrificed and their cauda epididymis and right testes dissected out for assessment of relevant parameters. Results: The results shows that seminal fluid parameters were not significantly different among the groups. There were no significant differences in body and organ weights among the groups. Group 2 rats (both testes/coitus) had a significantly reduced sperm count (p<0.05) compared with group 1 (both testes, no coitus). Sperm count was also significantly lower in group 3 (hemi-orchidectomized, no coitus) than in group 1 (both testes, no coitus) (p<0.05). Sperm count was significantly increased in group 4 (hemi-orchidectomy, with coitus) compared with group 2. Conclusion: We conclude that coitus may reduce sperm count in normal rats but does not have effect on sperm parameters in hemi-orchidectomized animals. However, orchidectomy increases sperm count in the contralateral testis.