Park S K, Grattan D R, Selmanoff M
Department of Physiology, University of Maryland, School of Medicine, Baltimore 21201-1559.
J Reprod Fertil. 1993 Sep;99(1):209-17. doi: 10.1530/jrf.0.0990209.
Hyperprolactinaemia inhibits gonadotrophin secretion in males and females of many species. The aim of this study was to determine the role of the adrenal gland in mediating the inhibitory effects of prolactin by contrasting the effects of acute hyperprolactinaemia on LH and FSH secretion in adrenal-intact and adrenalectomized rats with and without physiological corticosterone replacement. Adult male rats were administered purified ovine prolactin every 12 h (2.4 mg per injection s.c.) beginning at the time of castration. Blood samples were collected every 3 h for 36 h, then every 12 h until 10 days after castration. Ovine prolactin significantly reduced LH secretion in all groups from approximately 15 to 48 h after castration. In contrast, plasma FSH concentrations were reduced by ovine prolactin from 21 to 48 h only in the adrenal-intact rats and not in the adrenalectomized or adrenalectomized plus corticosterone groups. In all groups, ovine prolactin inhibited endogenous prolactin secretion in rats by short-loop autofeedback as soon as 3 h after the first ovine prolactin injection and throughout the 10 days of the study. Adrenalectomy per se, with or without corticosterone replacement, also had a differential effect on LH and FSH secretion after castration, causing only a transient delay in the rise in LH after castration, but inducing a significant and long-lasting inhibition of FSH secretion. The results demonstrate that ovine prolactin-induced suppression of LH secretion after castration occurs with or without the adrenal glands. Suppression of FSH secretion after castration by ovine prolactin, however, may involve an adrenal component.(ABSTRACT TRUNCATED AT 250 WORDS)
高催乳素血症会抑制许多物种雄性和雌性的促性腺激素分泌。本研究的目的是通过对比急性高催乳素血症对有肾上腺和去肾上腺大鼠（有无生理剂量皮质酮替代）促黄体生成素（LH）和促卵泡生成素（FSH）分泌的影响，来确定肾上腺在介导催乳素抑制作用中的作用。成年雄性大鼠在去势时开始每12小时皮下注射一次纯化的羊催乳素（每次注射2.4毫克）。在36小时内每3小时采集一次血样，然后每12小时采集一次，直至去势后10天。羊催乳素在去势后约15至48小时显著降低了所有组的LH分泌。相比之下，羊催乳素仅在有肾上腺的大鼠中在21至48小时降低了血浆FSH浓度，而去肾上腺大鼠或去肾上腺加皮质酮组则未降低。在所有组中，羊催乳素在首次注射后3小时及整个研究的10天内，通过短反馈自分泌抑制大鼠内源性催乳素分泌。去肾上腺本身，无论有无皮质酮替代，对去势后的LH和FSH分泌也有不同影响，仅导致去势后LH升高出现短暂延迟，但诱导FSH分泌显著且持久的抑制。结果表明，去势后羊催乳素诱导的LH分泌抑制在有或无肾上腺的情况下都会发生。然而，羊催乳素去势后对FSH分泌的抑制可能涉及肾上腺成分。（摘要截短至250字）
