Relationship of osmotic inhibition in thermoregulatory responses and sweat sodium concentration in humans.
Relationship of osmotic inhibition in thermoregulatory responses and sweat sodium concentration in humans.
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人体体温调节反应的渗透抑制与汗液钠浓度的关系。
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
Taketoshi Morimoto
中科院分区：
文献类型：
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作者：
Akira Takamata;Tetsuya Yoshida;Naoko Nishida;Taketoshi Morimoto
热习服改善了对热应激的体温调节反应，并降低了汗液钠浓度（[Na（+）]（汗液））。减少的[Na（+）]（汗液）导致在给定量的汗液输出下血浆渗透压（P（Cl））的较大增加。P（β 1）的增加抑制对增加的身体核心温度的体温调节反应。因此，我们推测，血浆高渗透压对热应激的体温调节反应的抑制作用应随着热习服引起的[Na（+）]（汗液）的减少而减弱。在等渗或高渗盐水输注后，通过将11名受试者（9名男性和2名女性）的小腿浸入42摄氏度（室温28摄氏度和相对湿度30%）的水中50分钟来被动加热。我们确定了在每种情况下引起出汗和皮肤血管舒张（CVD）所需的食管温度（T（es））的升高（分别为出汗和CVD的Δ T（es）阈值），并计算了每单位P（ERI）增加的T（es）阈值的升高，作为出汗和CVD的渗透抑制。出汗和CVD的DeltaT（es）阈值的渗透位移与[Na（+）]（汗液）呈线性相关（分别为r = 0.858和r = 0.628）。因此，[Na（+）]（汗液）较低的受试者显示出汗和CVD的DeltaT（es）阈值的渗透压升高较小。这些结果表明，热习服减弱体温调节反应的渗透抑制以及减少[Na（+）]（汗）的可能性。
Heat acclimatization improves thermoregulatory responses to heat stress and decreases sweat sodium concentration ([Na(+)](sweat)). The reduced [Na(+)](sweat) results in a larger increase in plasma osmolality (P(osmol)) at a given amount of sweat output. The increase in P(osmol) inhibits thermoregulatory responses to increased body core temperature. Therefore, we hypothesized that the inhibitory effect of plasma hyperosmolality on the thermoregulatory responses to heat stress should be attenuated with the reduction of [Na(+)](sweat) due to heat acclimatization. Eleven subjects (9 male and 2 female) were passively heated by immersing their lower legs into water at 42 degrees C (room temperature 28 degrees C and relative humidity 30%) for 50 min following isotonic or hypertonic saline infusion. We determined the increase in the esophageal temperature (T(es)) required to elicit sweating and cutaneous vasodilation (CVD) (DeltaT(es) thresholds for sweating and CVD, respectively) in each condition and calculated the elevation of the T(es) thresholds per unit increase in P(osmol) as the osmotic inhibition of sweating and CVD. The osmotic shift in the DeltaT(es) thresholds for both sweating and CVD correlated linearly with [Na(+)](sweat) (r = 0.858 and r = 0.628, respectively). Thus subjects with a lower [Na(+)](sweat) showed a smaller osmotic elevation of the DeltaT(es) thresholds for sweating and CVD. These results suggest the possibility that heat acclimatization attenuates osmotic inhibition of thermoregulatory responses as well as reducing [Na(+)](sweat).