Sunde A, Eik-Nes K B
J Steroid Biochem. 1982 Jul;17(1):77-84. doi: 10.1016/0022-4731(82)90595-7.
Testicular C19-steroid 7 alpha-hydroxylase activity rises during puberty in the rat. Hormonal mechanisms responsible for this rise are unknown. The present study is to the best of our knowledge the first to report successful stimulation of testicular 7 alpha-hydroxylase in immature rats. Administration of crude and purified hCG every day for 3 or more days to immature rats in doses of 3 I.U. lead to significant stimulation of testicular 7 alpha-hydroxylase activity. Purified preparations of subunits of hCG did not stimulate 7 alpha-hydroxylase activity. Stimulation of testicular 7 alpha-hydroxylase was, however, recorded when purified subunits of hCG were allowed to recombine and then administered to the animals. Several preparations of LH failed to cause stimulation of 7 alpha-hydroxylase when administered to immature rats. Treatment of immature rats with mixtures of LH and FSH, LH and prolactin or LH together with FSH and prolactin was also ineffective in this respect. Large doses of highly purified ovine-LH, rat LH and human LH were, however, able to stimulate testicular 7 alpha-hydroxylase activity in immature rats. Preparations comprising hybrids of ovine-LH and hCG (oLH alpha + hCG beta, hCG alpha + oLH beta) stimulated testicular 7 alpha-hydroxylase activity in immature rats. Administration of the same amounts of a hybrid preparation of human and ovine-LH (oLH alpha + hLH beta) to immature rats was ineffective in this respect. Administration of testosterone or estradiol to immature rats lead to suppression of testicular 7 alpha-hydroxylase activity. Combined treatment of such rats with hCG and testosterone or with estradiol and hCG augmented testicular 7 alpha-hydroxylase activity to the same degree as that of animals treated with hCG only.
大鼠青春期时睾丸C19-类固醇7α-羟化酶活性升高。导致这种升高的激素机制尚不清楚。据我们所知，本研究首次报道了在未成熟大鼠中成功刺激睾丸7α-羟化酶。以3国际单位的剂量每天给未成熟大鼠注射粗制和纯化的人绒毛膜促性腺激素（hCG）3天或更长时间，可显著刺激睾丸7α-羟化酶活性。hCG亚基的纯化制剂不能刺激7α-羟化酶活性。然而，当hCG的纯化亚基重新组合后再给予动物时，记录到了睾丸7α-羟化酶的刺激作用。几种促黄体生成素（LH）制剂在给未成熟大鼠注射时未能引起7α-羟化酶的刺激。在这方面，用LH和促卵泡激素（FSH）、LH和催乳素或LH与FSH和催乳素的混合物处理未成熟大鼠也无效。然而，大剂量的高度纯化的羊LH、大鼠LH和人LH能够刺激未成熟大鼠的睾丸7α-羟化酶活性。包含羊LH和hCG杂种的制剂（oLHα + hCGβ、hCGα + oLHβ）刺激未成熟大鼠的睾丸7α-羟化酶活性。在这方面，给未成熟大鼠注射相同量的人羊LH杂种制剂（oLHα + hLHβ）无效。给未成熟大鼠注射睾酮或雌二醇会导致睾丸7α-羟化酶活性受到抑制。用hCG和睾酮或雌二醇和hCG联合处理此类大鼠，可使睾丸7α-羟化酶活性增加到与仅用hCG处理的动物相同的程度。
