Ultee-van Gessel A M, de Jong F H
J Endocrinol. 1987 Apr;113(1):103-10. doi: 10.1677/joe.0.1130103.
The influence of age on testicular inhibin in untreated, neonatally hemicastrated and prenatally irradiated rats was studied using in-vivo and in-vitro experiments. In testicular cytosols prepared from 1-, 7-, 14-, 21-, 42- and 63-day-old rats concentrations of testicular inhibin could be measured with an in-vitro bioassay method using dispersed pituitary cells. Preparations of testicular cytosols caused a dose-dependent suppression of pituitary FSH secretion, whereas no effects were found on LH secretion. Testicular content of inhibin increased gradually with age, while after 14 days of age a relatively large increase of peripheral FSH concentrations occurred in all experimental groups. Neonatal hemicastration or prenatal irradiation resulted in decreased inhibin content of the testis and increased plasma FSH levels. The production of inhibin activity by Sertoli cells obtained from 7-, 14-, 21-, 42- and 63-day-old normal rats was measured during a 24-h incubation period on the third day of culture. The inhibin production per 10(6) plated Sertoli cells decreased rapidly after 14 days of age and the lowest production of inhibin was found in Sertoli cells from rats of 63 days of age. After pre-incubation with ovine FSH significantly larger amounts of inhibin activity were detected in spent media from 21-day-old rat testes. In contrast, suppression of inhibin production was found after pre-culture in the presence of testosterone at most of the ages studied. These data from in-vivo and in-vitro experiments indicate that a reciprocal relationship exists between pituitary FSH secretion and inhibin production before the age of 21 days.(ABSTRACT TRUNCATED AT 250 WORDS)
采用体内和体外实验研究了年龄对未处理、新生期半阉割及产前受照射大鼠睾丸抑制素的影响。用体外生物测定法，利用分散的垂体细胞，测定了1日龄、7日龄、14日龄、21日龄、42日龄和63日龄大鼠睾丸胞质溶胶中睾丸抑制素的浓度。睾丸胞质溶胶制剂引起垂体促卵泡激素（FSH）分泌呈剂量依赖性抑制，而对促黄体生成素（LH）分泌无影响。抑制素的睾丸含量随年龄逐渐增加，而14日龄后所有实验组外周FSH浓度相对大幅升高。新生期半阉割或产前照射导致睾丸抑制素含量降低和血浆FSH水平升高。在培养第三天的24小时孵育期内，测定了从7日龄、14日龄、21日龄、42日龄和63日龄正常大鼠获得的支持细胞抑制素活性的产生。每10⁶个接种的支持细胞的抑制素产生在14日龄后迅速下降，在63日龄大鼠的支持细胞中发现抑制素产生最低。用绵羊FSH预孵育后，在21日龄大鼠睾丸的培养液中检测到大量的抑制素活性。相反，在大多数研究年龄，在睾酮存在下预培养后发现抑制素产生受到抑制。这些体内和体外实验数据表明，在21日龄之前垂体FSH分泌与抑制素产生之间存在相互关系。（摘要截短于250字）
