Studies on the mechanism of growth hormone and thyrotropin responses to somatostatin antiserum in anesthetized rats.
Studies on the mechanism of growth hormone and thyrotropin responses to somatostatin antiserum in anesthetized rats.
复制标题
麻醉大鼠生长激素和促甲状腺素对生长抑素抗血清反应机制的研究。
作者：
K. Chihara;A. Arimura;M. Chihara;A. Schally
在乌拉坦或戊巴比妥麻醉的雄性大鼠中，静脉注射1 ml羊抗生长抑素（SS）抗血清，血清GH和TSH均显著升高，10--20min达高峰。抗SS抗体对血清PRL无影响。下丘脑基底内侧区的消融消除了抗SS给药后血清GH和TSH的升高。静脉注射1 ml兔抗TRH血清（anti-TRH）15 min后血清TSH水平下降，而注射正常兔血清对TSH水平无影响。在用抗TRH预处理的大鼠中，注射抗SS后血清TSH水平没有升高。另一方面，用抗TRH预处理不影响基础血清GH水平，也不影响抗SS诱导的GH释放。抗SS注射后GH和TSH的分泌增加并不被前列腺素合成抑制剂吲哚美辛预处理所阻断。结果表明：（1）抗SS的促生长素和促甲状腺激素反应都需要一个完整的下丘脑基底内侧;（2）抗SS的促甲状腺激素反应是由下丘脑促甲状腺激素释放激素（TRH）介导的;（3）抗SS的促生长素反应可能是由下丘脑促生长素释放激素（GH-releasing hormone，GH-releasing hormone）介导的。
An iv administration of 1 ml sheep antiserum to somatostatin (anti-SS) resulted in marked increases of both serum GH and TSH, with a peak 10--20 min after administration in male rats anesthetized with urethane or pentobarbital. Administration of anti-SS had no effect on serum PRL. Ablation of the basal medial hypothalamus abolished the rises of both serum GH and TSH after anti-SS administration. Intravenous injection of 1 ml rabbit antiserum to TRH (anti-TRH) decreased serum TSH levels 15 min after injection, whereas injection of normal rabbit serum did not affect TSH levels. Serum TSH levels did not rise after injection of anti-SS in rats pretreated with anti-TRH. On the other hand, pretreatment with anti-TRH did not affect the basal serum GH levels nor the anti-SS-induced GH release. The enhanced secretion of GH and TSH after anti-SS injections was not blocked by pretreatment with indomethacin, an inhibitor of prostaglandin synthesis. The following conclusions were made: 1) both GH and TSH responses to anti-SS require an intact basal medial hypothalamus; (2) TSH response to anti-SS is mediated by hypothalamic TRH; and 3) the GH response may be mediated by hypothalamic GH-releasing hormone which is not TRH or prostaglandins.