Cerebral metabolic responses and vasopressin and oxytocin secretions during progressive water deprivation in rats.
Cerebral metabolic responses and vasopressin and oxytocin secretions during progressive water deprivation in rats.
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大鼠进行性缺水期间的脑代谢反应以及加压素和催产素分泌。
DOI：
10.1152/ajpregu.1992.262.2.r310
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Eisenberg,HM
中科院分区：
文献类型：
--
作者：
Kadekaro,M;Summy-Long,JY;Freeman,S;Harris,JS;Terrell,ML;Eisenberg,HM
进行性缺水可增加血浆渗透压、血浆Na+浓度和红细胞压积，与脱水的严重程度成比例。随着血浆渗透压升高2%(24 h脱水)，视上核葡萄糖利用率增加，神经叶葡萄糖利用率有增加的趋势。随着进一步脱水，室旁核对葡萄糖的利用也增加。这些增加与神经叶中加压素和催产素含量的耗竭以及这两种激素分泌到血浆中的增加相平行，其中以加压素的增加为主。这些变化与脱水程度成正比。随着脱水的进展，细胞内和细胞外体积的减少加剧。细胞外体积的减少导致血管紧张素II(Ang II)的形成增加。相应地，脱水48小时和72小时后，血管紧张素转换酶II的主要作用部位穹隆下器(SFO)的葡萄糖利用率增加。从SFO接受直接输入的正中前视前核在这些时间段也增加了葡萄糖的利用。终板血管器的葡萄糖利用也增加，这可能是对渗透压受体、体积受体和血管紧张素Ⅱ受体的汇聚输入的反应。在尾侧和头端延髓腹外侧部观察到葡萄糖利用的减少，可能是对细胞外体积减少的代偿反应，以防止动脉血压下降。
Progressive water deprivation increased plasma osmolality, plasma Na+ concentration, and hematocrit in proportion to the severity of dehydration. With increases of 2% in plasma osmolality (24 h dehydration), glucose utilization increased in the supraoptic nuclei and tended to increase in the neural lobe. With further dehydration, glucose utilization also increased in the paraventricular nuclei. These increases were paralleled by depletion of vasopressin and oxytocin contents in the neural lobe and by the enhanced secretion of both hormones into plasma, with a predominant increase of vasopressin. These changes were proportional to the degree of dehydration. With progression of dehydration, decreases in intracellular and extracellular volumes accentuate. Reductions in extracellular volume result in increased angiotensin II (ANG II) formation. Accordingly, glucose utilization in the subfornical organ (SFO), a primary site of ANG II action, increased after 48 and 72 h of dehydration. The median preoptic nucleus, which receives direct inputs from the SFO, also increased glucose utilization at these times. Glucose utilization also increased in the organum vasculosum laminae terminalis, probably in response to the converging inputs from osmoreceptors, volume receptors, and ANG II receptors. Decreases in glucose utilization were observed in the caudal and rostral ventrolateral medulla, perhaps as compensatory responses to decreased extracellular volume to prevent fall in arterial blood pressure.