Benghuzzi H
Department of Health Sciences, School of Health Related Professions, University of Mississippi Medical Center, Jackson 39216, USA.
Biomed Sci Instrum. 1997;34:7-12.
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.
有充分文献记载，雄激素可刺激蛋白质合成代谢、肌肉发育、骨骼生长并提高代谢率。此外，外源性低水平睾酮可抑制垂体前叶促性腺激素的分泌。本研究的目的是通过磷酸三钙赖氨酸（TCPL）递送系统研究雄甾烷二酮（AD）持续递送对睾丸结构的影响。在本实验中，成年雄性Sprague Dawley大鼠（体重250 - 300 g）被随机分为三组，每组16只。第一组大鼠皮下植入装载AD的TCPL植入物。第二组大鼠植入假TCPL胶囊，第三组大鼠作为完整未植入的对照。按照标准实验室程序进行手术无菌操作。植入后2、4、8和16周结束时，每组处死4只动物，收集睾丸，称重并包埋以进行组织病理学评估。本研究结果如下：（1）与假手术组和完整对照组相比，4周阶段结束时睾丸重量显著降低，并在研究期间持续下降；（2）第一组动物的横断面显示，睾丸间质细胞大小和细胞器数量减少；（3）生精小管上皮高度和细胞数量减少；（4）8周阶段结束时，初级和次级精母细胞数量显著减少（分别为63%和78%），并且在第一组大鼠的12周阶段观察到无精子症；（5）在AD处理动物的组织中观察到数量略有减少。本实验证实了我们之前使用睾酮激素的研究结果，并表明外源性AD的低持续水平也会损害大鼠的生育能力。
