Investigation for roles of prostaglandins in the cerebral facilitatory mechanisms of antidiuretic hormone secretion

前列腺素在抗利尿激素分泌脑促进机制中的作用研究

基本信息

批准号：
06670076
负责人：
YAMAGUCHI Kenichi
金额：
$ 1.41万
依托单位：
NIIGATA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

1.In conscious rats iv infusion of hypertonic saline enhanced plasma antidiuretic hormone (ADH) 15 and 30 min later, and this was accompanied by an augmentation of plasma osmolality, sodium and chloride. The ADH response was abolished by local injection of meclofenamate, an inhibitor of prostaglandin biosynthesis, into the anteroventral third ventricular region (AV3V) 30 minbefore the onset of the hypertonic saline infusion. Factors other than plasma ADH were not affected by the meclofenamate injection significantly. The injection sites were confirmed histologically to have been in or near the organum vasculosum of the laminae terminalis, medial preoptic area, and periventricular and median preoptic nuclei. Local applications of PGE2 into such areas caused, 5 and 15 min later, remarkable increases in plasma ADH and arterial pressure, without affecting plasma osmolality and the electrolytes . These effects of PGE2 and meclofenamate were not observed when injection cnnulae were incidenta … More lly deviated from those AV3V sites to the cerebral ventricle near by, or when intended applications into the ventricle were performed. Therefore, it seems unlikely that the drugs administered into the AV3V produced the effects by acting on regions remote from it via diffusion through a stream of cerebrospinal fluid. On the other hand, AV3V injections of meclofenamate were without effect on plasma ADH and the other factors during iv infusion of isotonic saline.2.Effects of hyperosmolality on endogenous PGE2 levels were investigated, by establishing its determination methods by radioimmunoassay. Rats were infused iv with isotonic or hypertonic saline, and were decapitated for bloodcollection at 0,15 and 30 min. Plasma PGE2 level was not affected significantly by either isotonic or hypertonic saline. However, PGE2 concentration in the interstitial fluid obtained through microdialysis probes implanted into the AV3V one day before experiments tended to increase during the first 30 min period of hypertonic saline infusion performed over 60 min.The results mentioned above suggest that Pgs generated in and/or near the AV3V may contribute to facilitation of ADH secretion in the hyperosmotic state. Less

。在laminae末端，内侧和中位数核中，麦氯芬酸酯的注射症。因此，进行心室的应用。盐水。通过放射免疫分子或高渗盐水来研究内源性PGE2水平的效果。最初的30分钟盐水在60分钟内进行。在AV3V中进行的结果可能会导致促进ADH秘密的促进状态