Effects of Enviromental Temperature on Cardio-Vascular System in Experimental Animals

为探讨环境温度对实验动物心钠素（ANP）的影响，用生物遥测系统测定了热（33 ℃）和冷（15 ℃）环境条件下大鼠的血压（BP）、心率（HR）和体温（BT）。此外，通过免疫组织化学、电镜和放射免疫分析（RIA）检测两种环境条件下大鼠心房心肌细胞和血浆中ANP水平。(1)平均动脉血压、心率、体温：随着时间的推移，心率无明显变化，但血压、体温较对照组明显升高。然后，当热条件变为正常环境条件（22 ℃）时，这些参数在两三小时后恢复到正常水平。随着时间的推移，冷环境下血压和体温无明显变化，但心率较对照组明显增加。冷刺激1小时后心率恢复正常 ...更多信息 已转为正常状态。(2)血浆心钠素浓度：热应激状态下血浆心钠素浓度显著高于常温状态。当热条件变为正常环境时，3小时后浓度恢复至对照水平。在寒冷条件下，仅一小时后的浓度就显著高于正常条件下的浓度。(3)免疫组化和超微结构：热刺激后，心房肌细胞NP免疫反应性（IR）较正常强，热刺激24h后最强。然后，当热条件改变为正常环境时，IR在3小时后恢复到对照水平。在冷条件下，仅1小时后IR就比正常条件下强。超微结构上，心肌细胞中ANP颗粒的数量。热环境对循环心钠素及心血管系统有明显影响。少

To elucidate effects of environmental temperature on atrial natriuretic peptide (ANP) in experimental animals, the blood pressure (BP), heart rate (HR) and body temperature (BT) in rats under hot (33ﾟC) and cold (15ﾟC) environmental conditions were measured by a biotelemetridc system. Further, the ANP levels of auricular cardiocytes and plasma were examined by immunohistochemistry, electron microscopy, and radioimmunoassay (RIA) in rats under both environmental conditions. (1) Mean arterial BP,HR,BT : there is no change of HR,but BP and BT were significanlty increased under hot condition compared to the control level as time went by. Then those parameters were returned to normal levels after two or three hours when hot condition was changed to normal environmental condition (22ﾟC). There were no changes in BP and BT,but HR was significantly increased in cold condition compared to the control level as time went by. Then HR was returned to normal levels after one hour when cold condition … More was changed to normal condition. (2) Plasma ANP concentration : the concentration in hot condition was significantly higher than that in normal condition. When hot condition was changed to normal environment, the concentration was returned to control level after three hours. The concentration was significantly higher after only one hour in cold condition than that in normal condition. (3) Immunohistochemistry and ultrastructure : NP immunoreactivity (IR) in the auricular cardiocytes under hot condition was stronger than that in normal condition, and was strongest after 24 hours under hot condition. Then the IR was returned to the control level after three hours when hot condition was changed to normal environmenta. In cold condition, the IR was stronger after only one hour than that in normal condition. Ultrastructurally, the number of ANP-granules in the cardiocytes. with the stronger ANP-IR was greater that that with the weaker IR.The present study suggests that the circulating ANP and cardio-vascular systems are greatly influenced by hot environmental condition. Less