AGE EFFECTS ON NUMBER AND FUNCTION OF SERTOLI CELLS AND SPERMATOGONIA

越来越多的证据表明，睾丸激素起到了维持 这种类固醇通过与精子的相互作用而发生精子 支持细胞。因此，导致疾病的生理状况 支持细胞周围雄激素浓度的降低，或 导致这些细胞对 睾丸素，可能会导致睾丸产生减少 精子。在雄性大鼠中，睾丸老化是其特征 由于精子产量的下降和睾丸激素的减少 由莱迪格细胞生产。我们认为，在老年大鼠中， T产生减少导致睾丸内减少 睾丸激素浓度，从而导致Sertoli减少 细胞功能。而对生精细胞的影响 支持细胞功能减退，数量减少，或可能 茎精原细胞功能减退。概述了这些实验 这个应用程序将检验这一假设。首先，我们会 确定年龄和不同睾丸内的影响 睾酮浓度对大鼠数量和功能的影响 支持细胞。接下来，我们将考察年龄对年龄的影响 干细胞精原细胞分裂数和分裂速率。最后， 我们将研究睾丸内不同的睾丸素 浓度对茎精原细胞数量和功能的影响 在幼年老鼠和老年老鼠身上。

There is mounting evidence that testosterone acts to maintain spermato-genesis through the interaction of this steroid with Sertoli cells. Thus, physiological situations which lead to a diminution of androgen concentration around Sertoli cells, or which lead to a reduction in the ability of these cells to respond to testosterone, could lead to a reduced production of testicular spermatozoa. In the male rat, testicular aging is characterized by a decline in sperm production and by a decrease in testosterone production by Leydig cells. We suggest that in the aged rat, decreased T production leads to decreased intratesticular testosterone concentration, and therefore, to diminished Sertoli cell function. While the consequences to spermatogenic cells of a hypofunctional Sertoli cells and a reduced number, or possibly reduced function, of stem spermatogonia. The experiments outlined in this application will test this hypothesis. First, wee will determine the effect of age and different intratesticular testosterone concentrations on the number and functions of rat Sertoli cells. Next, we will examine the effect of age on the number and rate of cell division of stem spermatogonia. Finally, we will examine how different intratesticular testosterone concentrations affect the number and function of stem spermatogonia in young and old rats.