Spermatogenesis and the pituitary-testicular hormone axis in rats during the acute phase of spinal cord injury.

Male infertility frequently occurs after spinal cord injury (SCI). However, little is known about the acute effects of SCI on male reproductive function. This study evaluated the effects of SCI on spermatogenesis and testicular-pituitary function in rats 2 and 4 weeks after injury. Spinal cord injury was produced in rats by T9 spinal cord transection. Controls received similar surgery without transection. Complete spermatogenesis was seen 2 weeks after SCI; however, abnormalities were present in the seminiferous tubules. Hormone levels were similar in the two groups. Four weeks after SCI, incomplete spermatogenesis was noted in 3 of 9 rats, 4 others had delayed spermiation, and the last 2 had nonspecific regression of seminiferous epithelium. Serum testosterone levels were lower at 4 weeks in SCI rats than in controls, but testicular testosterone content was not. Plasma gonadotropin levels were similar in the two groups 4 weeks after SCI. Quantitative analysis revealed a 26 to 33% decrease in the number of spermatogenic cells in stage VII seminiferous tubules at 4 weeks in SCI rats (p < 0.01). This study demonstrated that qualitative and quantitative impairments of spermatogenesis occur during the acute phase of SCI in rats.