THERMAL DEHYDRATION-INDUCED THIRST

人类的热脱水与减少 工作能力，是中暑的一个主要因素。 热脱水引起的口渴对预防口渴很重要 热脱水的这些有害影响。目标是 所提出的研究是为了确定生理上的 热刺激引起口渴的途径 以大鼠为模型系统进行脱水实验。《公约》的具体目标 拟议的研究是为了a)确定 水的摄入量和热脱水的程度以及 确定b)渗透压升高，c)血容量减少， 以及d)热脱水引起的体温升高 口渴以及e)肾素血管紧张素系统的作用 肾上腺素能系统，g)胆碱能系统和h)阿片类药物 口渴的类型。将雄性大鼠作为实验动物 在这些研究中。大鼠将暴露在炎热的环境中(30-45 C)最多5小时不用水，以产生热量 脱水。离开暖气后的水摄入量将 与体温和人体测量结果相关 脱水的程度，如体重变化，红细胞压积， 血浆蛋白和钠浓度、血浆渗透压和 血浆肾素活性。选择性血浆容量置换 注射生理盐水或使渗透压恢复正常 将使用注水来确定低血容量症的作用 并在热脱水引起的口渴中增加渗透压。 对结肠和皮肤温度的实验操作将 用来研究体温在这类疾病中的作用 口渴。中枢性和外周性药物阻断 肾素血管紧张素系统、肾上腺素能、胆碱能和阿片类药物 受体将被用来研究这些系统在 来自这些研究的热脱水引起的口渴信息 对帮助我们理解热有直接的重要性-- 诱发口渴，并应协助设计干预措施，以预防 热脱水及其对健康的影响。

Thermal dehydration in humans is associated with a decrease in work capacity and is a major contributing factor to heat stroke. Thirst induced by thermal dehydration is important in preventing these detrimental effects of thermal dehydration. The objective of the proposed research is to determine the physiological pathways involved in the thirst observed following thermal dehydration using rats as a model system. Specific aims of the proposed research are to a) determine the relationship between water intake and the degree of thermal dehydration and to determine the roles of b) increased osmolality, c) hypovolemia, and d) increased body temperature in thermal dehydration-induced thirst as well as the roles of the e) reninangiotensin system, f) adrenergic system, g) cholinergic system and h) opiates in this type of thirst. Male rats will be used as the experimental animal in these studies. Rats will be exposed to a hot environment (30-45 degree C) without water for up to 5 hours to induce thermal dehydration. Water intake following removal from the heat will be correlated with body temperatures and measurements of the degree of dehydration such as body weight changes, hematocrit, plasma protein and sodium concentrations, plasma osmolality and plasma renin activity. Selective replacement of plasma volume with saline administration or returning osmolality to normal with water infusion will be used to determine the roles of hypovolemia and increased osmolality in thermal dehydration-induced thirst. Experimental manipulations of colonic and skin temperature will be used to study the role of body temperatures in this type of thirst. Central and peripheral pharmacologic blockade of the reninangiotensin system, adrenergic, cholinergic and opiate receptors will be used to study the roles of these systems in thermal dehydration-induced thirst Information from these studies will be of direct importance in aiding our understanding of heat- induced thirst and should aid in designing interventions to prevent thermal dehydration and its health consequences.