Wakabayashi I, Hatano H, Minami S, Tonegawa Y, Akira S, Sugihara H, Ling N C
Brain Res. 1986 May 7;372(2):361-5. doi: 10.1016/0006-8993(86)91145-5.
Female and male rats were treated with monosodium glutamate (MSG; 4 mg/g b. wt.) as neonates and the capability of the pituitary gland to secrete growth hormone (GH) in response to an intravenous injection of human GH-releasing factor (GRF) was evaluated under pentobarbital anesthesia on 109 days of life. Immunoreactive GRF content in the pituitary stalk-median eminence tissue in MSG-treated rats was less than 20% of that of control. A significant dose-dependent plasma GH response was observed after the administration of two doses of human GRF (0.25 and 1 microgram/kg b. wt., i.v.) in both control and MSG-treated rats. The responses between MSG-treated and control rats were comparable in female rats, but they were significantly reduced in male MSG-treated rats. These results show that the pituitary's responsiveness to exogenous GRF is well preserved in MSG-treated rats despite prolonged and severe depletion of endogenous GRF and there exists a sex difference in the effect of MSG on GH secretion elicited by GRF.
新生雌性和雄性大鼠用谷氨酸单钠（MSG；4mg/g体重）处理，在出生后第109天，于戊巴比妥麻醉下评估垂体对静脉注射人生长激素释放因子（GRF）分泌生长激素（GH）的能力。MSG处理大鼠垂体柄-正中隆起组织中免疫反应性GRF含量不到对照组的20%。在对照组和MSG处理大鼠中，静脉注射两剂人GRF（0.25和1μg/kg体重）后，观察到显著的剂量依赖性血浆GH反应。在雌性大鼠中，MSG处理组和对照组之间的反应相当，但在雄性MSG处理大鼠中，反应显著降低。这些结果表明，尽管内源性GRF长期严重耗竭，但MSG处理大鼠垂体对外源性GRF的反应性仍得到良好保留，且MSG对GRF引起的GH分泌的影响存在性别差异。
