Prolactin involvement in regulation of testicular 5 alpha-reductase activity in the immature rat.
Prolactin involvement in regulation of testicular 5 alpha-reductase activity in the immature rat.
复制标题
催乳素参与未成熟大鼠睾丸 5α-还原酶活性的调节。
DOI：
10.1095/biolreprod33.3.637
复制
发表时间：
1985
影响因子：
3.6
通讯作者：
Payne,AH
中科院分区：
文献类型：
--
作者：
Chase,DJ;Payne,AH
溴过隐碱（BR）抑制泌乳素（Prl）的分泌，可降低未成熟（25日龄）大鼠睾丸5α-还原酶的活性，而溴过隐碱（Prl）可提高泌乳素处理动物睾丸5α-还原酶的活性。血清促黄体生成素（LH）浓度未因BR处理而降低，也未因Prl处理而升高，表明BR和Prl对酶活性的影响不是由于LH分泌的改变。垂体切除术（21日龄）导致睾丸5α-还原酶活性急剧下降，LH治疗部分逆转了这一作用。单独用Prl治疗垂体切除动物对酶活性无影响，但可增强LH的作用。给去垂体的动物注射丙酸睾酮，使睾丸睾酮浓度至少达到完整（假去垂体）对照组的水平，无论单独给药还是与LH联合给药，对酶活性都没有影响。提示Prl与LH共同参与了维持青春期前大鼠睾丸5α-还原酶高活性的过程；Prl的作用，显然需要LH的存在，可能是降低酶的降解速率。这些数据还表明，LH对睾丸5α-还原酶活性的作用不是通过刺激睾丸激素的产生来介导的。
Treatment of intact immature (25-day-old) rats with bromoergocryptine (BR), which suppressed prolactin (Prl) secretion, decreased testicular 5α-reductase activity, whereas treatment with Prl increased the enzyme activity in BR-treated animals. Serum luteinizing hormone (LH) concentrations were not reduced by BR treatment or elevated by Prl, suggesting that the BR and Prl effects on enzyme activity were not due to alterations in LH secretion. Hypophysectomy (at 21 days of age) caused a dramatic decrease in testicular 5α-reductase activity, and treatment with LH partially reversed this effect. Treatment of hypophysectomized animals with Prl alone had no effect on the enzyme activity but enhanced the effect of LH. Testosterone propionate, given to hypophysectomized animals in a regimen that increased testicular testosterone to concentrations at least as high as those in intact (sham-hypophysectomized) controls, had no effect on enzyme activity, whether given alone or in combination with LH.These results indicate that Prl is involved, along with LH, in maintaining the high 5α-reductase activity of the prepubertal rat testis; the action of Prl, apparently requiring the presence of LH, may be to decrease the rate of degradation of the enzyme. The data also suggest that the action of LH on testicular 5α-reductase activity is not mediated by its stimulation of testosterone production.