【摘要】 目的和方法 :采用放射性同位素法观察发热和低体温大鼠下丘脑中腺苷酸环化酶 (AC)活性与cAMP含量的经时变化。结果 :(1)鲜酵母皮下注射后 4h引起体温明显升高 (P <0 0 1) ,并长时间维持在高位水平 ,AC活性在造模后 3h达峰值 (P <0 0 5 ) ,其后活性迅速下降 ,历 3h又再度上扬超出正常水平 (P <0 0 1) ;cAMP含量的变化是由低渐高 ,且与体温的变化趋势相似。 (2 )安痛定腹腔注射后 15min动物即呈现低体温状态 (P <0 0 5 ) ,在造模后45minAC活性及cAMP含量均降至最低点 (P <0 0 5 ) ,其后AC活性及cAMP含量均逐步回升至正常水平。结论 :(1)在发热模型中 ,下丘脑AC活性的增强使细胞内cAMP含量增多是动物体温升高的重要原因。 (2 )在低体温模型中 ,AC活性的明显下降以及cAMP含量的明显减少表明cAMP与动物的低温状态有关 ,但降温的始动环节不依赖于cAMP。更多还原

【Abstract】 AIM: To observe the changes of AC activity and content of cAMP at different time point in hypothalamus of rats with fever and hypothermia. METHODS: Radioisotope method was used to measure the enzymatic activity of AC and the content of cAMP. RESULTS:(1)The fresh yeast caused fever after making model 4 h( P< 0.01). AC activity reached a peak value 3 h after making model ( P< 0.05), subsequently AC activity rapidly decreased and increased again over normal level ( P< 0.01);The change of cAMP content was positively related to the body temperature. (2) Aminopyrine induced rat hypothermia state after making model 15 min ( P< 0.05). AC activity rapidly weakened and cAMP content rapidly descended to the lowest value at making model 45 min, subsequently AC activity and cAMP content in hypothalamus gradually increased again to normal range. CONCLUSION: (1)In fever model, it might be an important cause of febrile response that AC induced increase in intracellular cAMP content; (2) In hypothermia model, the significant decrease of AC activity and cAMP content indicate that cAMP might play a role in keeping hypothermia.更多还原