| Co-Investigator(Kenkyū-buntansha) |
NISHIZUKA Masako Sch. of Med., Juntendo Univ., 医学部, 講師 (20133332)
MORI Takao Zool. Inst., Fac. of Sci., Univ. of Tokyo, 理学部, 助教授 (80011659)
ISHII Susumu Sch. of Educat ion, Waseda Univ., 教育学部, 教授 (90063528)
SEO Hisao Inst. for Environm. Med., Nagoya Univ., 環境医学研究所, 助教授 (40135380)
TANAKA Fukuko Sch. of Med., Yokohama City Univ., 医学部, 教授 (40046066)
|
|---|
| Research Abstract |
Age-related changes of renal and reproductive endocrine systems including the neuroendocrine system in higher vertebrates were studied by means of morphological, endocrinological, physioliogical, harmacological and molecular biological techniques. During the last two years of this co-operative research, the following new findings were obtained.
1. The quantitative method of lipofuscin accumulation in cultured dissociated cells from the brain of rats and mice was established. Vitamin E was proved to be effective in reducing the storage of lipofuscin in cultured cells. 2. Steroid hormones, in particular, estrogen and nerve growth factors were proved to be important factors for the development of preoptic-hypothalamic and limbic systems in the rat. 3. In order to analyze the cause of elevated prolactin secretion in the rat at advanced ages, cultured pituitary cells were given dopamine and dopamine precursor. It was evident that there was clear age-related changes in the responsiveness to these agents. 4. Reverse hemolytic plaque assay was established to analyse the amount of hormones secreted in a single cell. The assay system was effective in demonstrating the inhibitory effect of dopamine on prolactin secretion. 5. The amount of prolactin mRNA was less in prolactin-secreting spontaneous adenoma in old rats than estrogen-induced pituitary adenoma in young rats. 6. The decreased secretion of growth hormone in old rats was related to-the decrease in in amount of growth hormone mRNA. 7. Multiple parameters in Wistar/Tw rats showing polydipsia and polyuria at middle ages were established, such as, water metabolism, creatinine metabolism, plasma levels of vasopressin and oxytocin. The occurrence of polydipsia and polyuria was earlier in males and females. Experimental results showed that androgen accelerates the occurrence.
Many of the initial questions were answered by this two-year cooperative research. However, several new questions for further analyses have arisen.
|
