Quantitative (stereological) study of the effects of vasectomy on spermatogenesis in rhesus monkeys (Macaca mulatta)

in Reproduction
View More View Less

Vasectomy reversal by vasovasostomy after long-term vasectomy in men results in lower sperm counts and pregnancy rates compared with controls, and severe damage to spermatogenesis has been observed in some animal models such as mice. The primary aim of this study was to evaluate, using sophisticated stereological methods, whether vasectomy of 6 and 12 months in a non-human primate would lead to, among other morphometric changes, reduced numbers of germ cells in testes and spermatozoa in epididymides. Five normal adult male rhesus monkeys (Macaca mulatta) underwent bilateral vasectomy, with another three aged-matched normal monkeys not undergoing vasectomy. One testis together with the ipsilateral epididymis was removed from each animal at 6 months, and the other testis and epididymis, the prostate gland and seminal vesicles were removed at 12 months. Various morphometric data were obtained using stereological methods and an unbiased and efficient stereological tool, the optical disector, was used to estimate nuclear numbers of all types of spermatogenic cells in testes and spermatozoa in epididymides using methacrylate-embedded sections 25 microm in thickness. As shown by a two-way repeated measures analysis of variance, vasectomy or hemicastration (removal of the organs at 6 months) had no significant effects on all quantitative parameters of stereology obtained from the testis, epididymis, prostate gland and seminal vesicle, except that (i) sperm granuloma was observed from three of five vasectomized animals both at 6 and 12 months, and (ii) hemicastration significantly reduced the diameter of the seminiferous tubules and increased the number of type A spermatogonia per testis. In conclusion, vasectomy in the non-human primate is a safe procedure in terms of effects on the structures of the reproductive organs.

If the inline PDF is not rendering correctly, you can download the PDF file here.


     An official journal of

    Society for Reproduction and Fertility


Sept 2018 onwards Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 209 40 5
PDF Downloads 176 55 5