脱水式热暴露对大鼠生理指标和IL-2、IL-6及IgG含量的影响

The Influence of Dehydration Thermal Exposure at Different Levels on Physiological and Biochemical Parameters in Rats

目的探讨长时间不同强度的热暴露对大鼠体重、血压、心率、脏器系数及免疫因子的影响。方法雄性SD大鼠,随机分为对照组(24℃)、中等强度热暴露组(32℃)、高强度热暴露组(38℃)。经5周热暴露后观察大鼠行为,记录体重差;监测心率及血压;取大鼠胸腺、脾脏、心脏、下丘脑、垂体计算脏器系数;测定血浆白介素2(IL-2)、白介素6(IL-6)及免疫球蛋白G(IgG)的含量。结果与对照组比较,两种热暴露组的体重差值的增高均具有统计学意义(P<0.01),且在热暴露第1周和第2周,高强度热暴露组体重差值高于中等强度热暴露组,差异具有统计学意义(P<0.05);与对照组比较,中等强度热暴露组的胸腺指数明显增高(P<0.05),与对照组比较,高强度热暴露组的脾脏指数明显降低(P<0.05),与中等强度热暴露组比较,高强度热暴露组的胸腺和脾脏指数均显著降低(P<0.05),其他脏器系数的变化无统计学意义(P>0.05)。心率、血压、血浆中IL-2、IL-6及IgG含量虽有不同程度的变化,但差异无统计学意义(P>0.05)。结论适当的外界温度可使大鼠产生热适应,提高免疫功能,增强机体抵抗外界不利环境的能力;高温刺激则可能使大鼠免疫功能遭受损伤。

Objective To explore the effect of different levels of thermal exposure on weight,blood pressure,heart rate,organ coefficient and immune factor in rats. Methods Male SD rats were randomly divided into control group,moderate heat exposure group,high strength heat exposure group. The activities and the weight difference of rats were observed and recorded. Blood pressure and heart rate were measured. The thymus,spleen,heart,hypothalamus,hypophysis were removed and organ coefficient was calculated. Venous blood samples were collected from the postcava and the immune factors were detected. Results Compare with control group,the differences of body weight of the high strength heat exposure group was significantly higher than that of the moderate heat exposure group on the first week and the second week( P < 0. 05). Compare with control group,the organ coefficient of thymus of moderate heat exposure group was increased significantly( P <0. 05) while the organ coefficient of spleen of high strength heat exposure was decreased significantly( P <0. 05). Compare with moderate heat exposure group,the coefficient of spleen and thymus were decreased significantly( P < 0. 05). The heart rate,blood ressure,content of IL- 2,IL- 6 and IgG were showed no significant changes among groups( P > 0. 05). Conclusion The body obtains the ability of heat acclimation at an appropriate temperatures,on the contrary,high temperature can cause immune damage.