TCPL delivery system: the role of sustained delivery of testosterone enanthate on the fine structure of seminiferous tubule of adult male rats

It is well documented that testosterone stimulates protein anabolism, muscular development, bone growth and increased metabolic rate. In addition, exogenous low level of testosterone can inhibit the secretion of gonadotropins by the anterior pituitary. The objective of this study was to investigate the effect of sustained delivery of testosterone enanthate (TE) on the testicular architecture by means of tricalcium phosphate lysine (TCPL). In this experiment adult male Sprague Dawley rats (250-300 g BW) were randomly divided into three equal groups (n=16). Rats in group I were implanted subcutaneously with TE loaded TCP implants (4-6 ng/ml). Rats in group II were implanted with sham TCP capsules, and rats in group III served as intact unimplanted controls. Surgical aseptic techniques were performed according to standard laboratory procedures. At the end of 2 and 4 weeks post implantation, 8 animals from each group were sacrificed and the testes were collected, weighted, and embedded for histopathological evaluations. The results of this study revealed the following: (i) Sustained delivery of TE reduced spermatogonia numbers in animals after 2 and 4 weeks by approximately 10% in comparison to control animals. (ii) The lumen of the tubules showed slight regression after 4 weeks of TE treatment. (iii) Overall decrease of the vasculature of the experimental animals was seen after 2 and continued through 4 weeks with an occasional increase of microvasculature seen in animals treated for 4 weeks with TE. (iv) Finally, the germinal epithelium showed significant reduction in secondary spermatocytes and conversion to mature sperm