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Mechanism of maturation and aging of reproductive endocrine system in mammals.

哺乳动物生殖内分泌系统成熟和衰老的机制。

基本信息

批准号：
59440004
负责人：
KAWASHIMA Seiichiro
金额：
$ 9.92万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (A)
财政年份：
1984
资助国家：
日本
起止时间：
1984 至 1986
项目状态：
已结题

项目摘要

The mechanism of maturation and aging of the hypothalamus, pituitary and peripheral endocrine organs has been studied during the last three years by means of various techniques including cell culture, radioreceptor assay, radioimmunoassay, electron microscopy and immunocytochemistry. Important conclusions arrived at in individual research titles which as a whole comprise the present project are summarized as follows.1. Steroidal effects on the development of sexual dimorphism. Estradiol and testosterone stimulated the neuronal process growth and sprouting in cells derived from the hypothalamus-preoptic area of fetal and neonatal rats in monolayer culture, while dihydrotestosterone was not effective. This indicates the importance of aromatization of testosterone to estrogen for the manifestation of sexual dimorphism of the brain.2. Neuronal aging. Lipofuscin storage as a parameter of aging of neurons in culture was inhibited by tocopherol and its derivatives. For another parameter of neuronal aging, plasticity of neurosecretory neurons was studied. After hypophysectomy in mice, the increase in the number of fibers in the external layer of the median eminence was greater in young than old animals, suggesting a decrease in axonal plasticity in old mice.3. Prolactin cells and secretion. Differentiated prolactin cells underwent mitosis in male and femela rats, but sexual difference was present in the prolactin cell population and mitotic activity throughout most of the postnatal life.4. Regulatory mechanism of gonadotropin receptors. The use of hypophysectomized animals showed that follicle stimulating hormone (FSH) is needed for the induction of FSH receptors. However, in mice after puberty hypophysectomy increased FSH receptors and FSH administration reduced them, suggesting the role of downregulation. This finding was reinforced by electron microscopic autoradiography.

近三年来，人们利用细胞培养、放射受体分析、放射免疫分析、电镜和免疫细胞化学等技术，对下丘脑、垂体和外周内分泌器官的成熟和衰老机制进行了研究。本项目的主要研究成果概括如下：1.类固醇激素对两性异形发育的影响。雌二醇和睾酮刺激单层培养的胚胎和新生大鼠下丘脑-视前区细胞的神经突起生长和发芽，而双氢睾酮则无效。这表明睾酮芳构化为雌激素对于大脑性别二型性表现的重要性.神经元老化。生育酚及其衍生物可抑制脂褐素贮存作为神经元老化的一个参数。对于神经元老化的另一个参数，神经分泌神经元的可塑性进行了研究。小鼠垂体切除后，年轻组正中隆起外层神经纤维数量的增加大于老年组，提示老年组轴突可塑性降低.催乳素细胞和分泌。分化的催乳素细胞在雄性和雌性大鼠中均进行有丝分裂，但在出生后的大部分时间内催乳素细胞的数量和有丝分裂活性存在性别差异.促性腺激素受体的调节机制。垂体切除动物的使用表明，卵泡刺激素（FSH）是诱导FSH受体所必需的。然而，在青春期后的小鼠中，垂体切除术增加了FSH受体，FSH给药减少了它们，这表明了下调的作用。电子显微镜放射自显影证实了这一发现。