Interactive effect of osmoregulatory and volume regulatory stimuli on thermoregulation.

渗透压调节和容量调节刺激对体温调节的相互作用。

基本信息

批准号：
14570064
负责人：
TAKAMATA Akira
金额：
$ 2.24万
依托单位：
Nara Women's University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

To gain better insights into the interaction between fluid regulatory and thermoregulatory systems, we examined the effect of body fluid regulatory stimuli on thermoregulatory responses in human subjects.Upright posture reduced thermogenesis in response to body core cooling, compared with supine position. In contrast, upright posture enhanced peripheral vasoconstriction. Therefore, the thermoregulatory response to cold stress is influenced by volume regulatory system. The results also suggest that the mechanisms controlling peripheral vasoconstriction and thermogenesis during cold stress are appeared to be independent. We also examined the effect of plasma hyperosmolality on baroreceptor unloading-induced peripheral vasoconstriction. Plasma hyperosmolality augmented the reduction of forearm vascular conductance induced by lower body negative pressure during heat stress but not during normothermia. Therefore, there. apparently exists an interactive effect of plasma hyperosmolality and c … More entral hypovoloemia on the peripheral vascular response during heat stress, but not during normothermia. Our findings suggest that plasma hyperosmolality enhances baroreceptor-mediated reduction of thermal active peripheral vasodilation, but does not enhance the vasoconstrictor system.In a series of animal experiments, we examined the central mechanisms of the body fluid regulatory system. We quantified the permeability of capillaries in the subfornical organ of rat by a nuclear magnetic resonance method in combination with a venous injection of a relaxation reagent, Gd-DTPA^<2-> which could not pass through the blood-brain barrier (BBB). The proposed value may be 10-100 times larger than that of the blood-barrier in the cortex. We conclude that the capillaries in the SFO have one of the highest water permeability values among all of the capillaries in the brain, and this site may play an important role in osmoreception. In another animal experiment, we suggest that Mn^<2+> MRI is a useful technique for identifying in vivo the active brain region in the hypothalamus in response to various stimuli. Less

为了更好地了解流体调节和热调节系统之间的相互作用，我们研究了人体液体调节刺激对人类受试者中温度调节反应的影响。与仰卧位相比，对手姿势对人体核心冷却的响应减少了热生成。相反，直立的姿势增强了外周血管收缩。因此，对冷应激的热调节反应受体积调节系统的影响。结果还表明，控制周围血管收缩和冷应激过程中的热发生的机制似乎是独立的。我们还研究了血浆高渗透率对压力受体卸载引起的外周血管收缩的影响。血浆高温性增加了在热应激期间下身体负压诱导的前臂血管电导的减少，而在近期炎症过程中却不是。因此，那里。显然，血浆高体积性和C…在热应激期间对周围血管反应的互动效果，但在近期炎症过程中没有。我们的发现表明，血浆过度渗透性增强了压力感受器介导的热活性周围血管舒张的减少，但不会增强血管收缩系统。在一系列动物实验中，我们检查了体液调节系统中核量的核纳入capilloriase capillaries的中心机制。注射松弛试剂GD-DTPA^<2->无法通过血脑屏障（BBB）。所提出的值可能是皮质中血脑屏障的10-100倍。我们包括SFO中的毛细血管在大脑中所有毛细血管中具有最高的水渗透率之一，并且该部位可能在孔隙受体中起重要作用。在另一个动物实验中，我们建议MN^<2+> MRI是一种有用的技术，可用于响应各种刺激，在体内识别下丘脑中的活性大脑区域。