Role of LHRH in the gonadotrophin response to restraint stress in intact male rats.
Role of LHRH in the gonadotrophin response to restraint stress in intact male rats.
复制标题
LHRH 在完整雄性大鼠促性腺激素对束缚应激反应中的作用。
DOI：
--
复制
发表时间：
1990
影响因子：
4
通讯作者：
C. Ariznavarreta
中科院分区：
文献类型：
--
作者：
A. López;M. González;J. Tresguerres;C. Ariznavarreta
慢性应激对促性腺激素分泌的抑制作用已被假设为下丘脑的作用部位。本研究旨在观察慢性应激大鼠下丘脑LHRH含量和促性腺激素分泌的时间变化，以及垂体对LHRH刺激的反应性。成年雄性大鼠分别于2、3、4 d内，每天禁闭0、20、45、90、180、360 min或6 h后处死。应激20 ~ 45 min后，血浆LH浓度升高（P < 0.01），下丘脑LHRH含量降低（P < 0.01），提示血浆LH与下丘脑LHRH浓度呈负相关。抑制后血浆FSH浓度也升高，但FSH反应较慢且低于血浆LH反应，在抑制90 min后表现明显。慢性应激大鼠血浆LH、FSH和下丘脑LHRH浓度降低。在连续4天每天限制6小时的大鼠中，注射500 ng LHRH后45分钟血浆促性腺激素的反应增强。在这些观察的基础上，我们得出结论，在完整的大鼠中，应激可能会急性刺激LHRH和促性腺激素的分泌，慢性应激对血浆LH和FSH的抑制作用似乎不是由于垂体对LHRH的反应性降低，而是由于LHRH分泌减少。
A hypothalamic site of action has been hypothesized for the inhibitory effect of chronic stress on gonadotrophin secretion. The aim of the present study was to examine the temporal changes in hypothalamic LHRH content and gonadotrophin secretion during restraint stress, and the pituitary responsiveness to LHRH stimulation in chronically stressed rats. Adult male rats were killed after being restrained for 0, 20, 45, 90, 180 and 360 min or for 6 h daily over 2, 3 and 4 days. After 20-45 min of stress there was an increase in plasma concentrations of LH (P less than 0.01) and a decrease in hypothalamic LHRH content (P less than 0.01), suggesting a negative correlation between plasma LH and hypothalamic LHRH concentrations. Plasma concentrations of FSH were also increased by restraint, but the FSH response was slower and less than the plasma LH response, being significant after 90 min of restraint. Plasma LH and FSH and hypothalamic LHRH concentrations were decreased in chronically stressed rats. In rats restrained for 6 h daily over 4 days, the response of plasma gonadotrophins to administration of 500 ng LHRH was enhanced 45 min after the injection. On the basis of these observations we concluded that in the intact rat, stress may acutely stimulate LHRH and gonadotrophin secretion, and the inhibitory effect of chronic stress on plasma LH and FSH seems not to be due to a reduction in pituitary responsiveness to LHRH, but rather to a decrease in LHRH secretion.