The effect of sustained delivery of androstanedione on the functional activities of adult male rats.

It is well documented that androgens stimulate protein anabolism, muscular development, bone growth and increased metabolic rate. In addition, exogenous low levels 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 androstanedione (AD) on the testicular architecture by means of tricalcium phosphate lysine (TCPL) delivery system. 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 TCPL implants loaded with AD. Rats in group II were implanted with sham TCPL 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, 4, 8 and 16 weeks post implantation, four 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: (1) remarkable reduction of testicular mass at the end of the 4 week phase and continued for the duration of study in comparison to the sham and intact control; (2) cross sections obtained from group I animals have shown that the Leydig cells were decreased in size and number of organelle; (3) the epithelium of the seminiferous tubules decreased in height and cell number; (4) a significant decrease (p < 0.05) in the number of primary and secondary spermatocytes (63% and 78% receptively) at the end of the 8 week phase, and azoospermia was observed at the 12 week phases in group I rats; and (5) slight reduction in the number of was observed in tissues obtained AD treated animals. This experiment confirms our previous findings using testosterone hormone and demonstrates that low sustained levels of exogenous AD can also impair fertility in rats.