Greeley G H, Nicholson G F, Nemeroff C B, Youngblood W W, Kizer J S
Endocrinology. 1978 Jul;103(1):170-5. doi: 10.1210/endo-103-1-170.
Adult rats which have received monosodium-L-glutamate (MSG, 4 mg/g BW) on alternate days for the first 10 days of life manifest central nervous system lesions largely restricted to the retina and the arcuate nucleus of the hypothalamus in which nearly 90% of the perikarya are destroyed, leaving axons in passage intact. In animals so treated, concentrations of dopamine within the arcuate nucleus and median eminence of the hypothalamus are reduced 52% and 57%, respectively, in males and 45% and 61% in females, whereas concentrations of norepinephrine in these same two areas are normal. Concentrations of both norepinephrine and dopamine in five other hypothalamic nuclei (dorsal septal, medial preoptic, suprachiasmatic, periventricular, and dorsomedial nuclei) are unchanged. Nevertheless, despite the destruction of the arcuate nucleus cell bodies of MSG-treated rats, postcastration levels of serum FSH and LH in males, and FSH in females were not significantly different from FSH and LH values in castrated controls. Serum LH in castrated, MSG-treated females was slightly but significantly lower than in castrated controls. It is concluded that the arcuate nucleus-median eminence tuberoinfundibular neurons are not of primary importance in the tonic, negative feedback regulation of gonadotropin secretion.
在出生后的头10天，每隔一天给成年大鼠注射L-谷氨酸单钠（MSG，4毫克/克体重），结果显示中枢神经系统损伤主要局限于视网膜和下丘脑弓状核，其中近90%的神经细胞体被破坏，而轴突保持完整。在接受如此处理的动物中，下丘脑弓状核和正中隆起内的多巴胺浓度，雄性分别降低52%和57%，雌性分别降低45%和61%，而这两个区域的去甲肾上腺素浓度正常。其他五个下丘脑核（背中隔核、内侧视前核、视交叉上核、室周核和背内侧核）中的去甲肾上腺素和多巴胺浓度均未改变。然而，尽管MSG处理的大鼠弓状核细胞体被破坏，但雄性大鼠去势后的血清促卵泡激素（FSH）和促黄体生成素（LH）水平，以及雌性大鼠的FSH水平与去势对照的FSH和LH值并无显著差异。MSG处理的去势雌性大鼠的血清LH略低于去势对照，但差异显著。结论是，弓状核-正中隆起-结节漏斗神经元在促性腺激素分泌的紧张性负反馈调节中并非至关重要。
