The effect of unilateral vasectomy on testosterone and testicular parameters in the adult male African giant rat (Cricetomys gambianus)

FIO Duru, S Ajayi, OO Azu

Abstract

Background: The effects of vasectomy on spermatogenesis and  reproductive parameters are recognized to be speciedependent with marked differences in levels of perturbations observed.
Objectives: To assess the impact of unilateral vasectomy on testosterone level and other testicular parameters in the male African giant rat (AGR) (Cricetomys gambianus).

Methods: Sixteen adult male AGRs weighing 500-1300 g were recruited for the experiment. Animals were randomly divided into three experimental groups (1-3) and one control (sham operated) group with four rats per group. Experimental vasectomy was done by carefully ligating the vas deferens of the right testis of all the experimental groups (1, 2, and 3) and animals were allowed either 8, 6 and 2 weeks respectively before sacrifice. Sham-operated animals served as the control. Blood samples were collected and assayed for testosterone while testicular tissue was further processed for seminal fluid and histo-pathological analyses.

Results: Spermatogenic parameters indicate a pattern of decline in sperm count and motility between the experimental groups and the control and azoospermia in the eight-week group. Histological alterations were marked by atrophy of seminiferous tubules which was proportional to the duration of vasectomy. Serum testosterone levels were significantly reduced at eight weeks. There was no statistically significant difference between sperm counts of right and left testes except for group 3. Results suggest that unilateral vasectomy of the AGR may have negative impact on the  contralateral testis in the male African giant rat.

Conclusion: These preliminary results reveal that unilateral vasectomy in the AGR may result in perturbations of the histoarchitecture of the testes with possible decline in function.

Key words: African giant rat, vasectomy, testis.