脓毒症大鼠心肌腺苷酸环化酶活性的变化及其机理探讨

A STUDY ON THE MECHANISM OF THE CARDIAC ADENYLYL CYCLASE ACTIVITY ALTERATION IN SEPTIC RATS

本研究证明，脓毒症（结扎盲肠及穿刺，ＣＰＬ）大鼠心肌肌膜腺苷酸环化酶（ＡＣ）的活性及其部分纯化的ＡＣ最大活性，在早期脓毒症（ＥＳ，ＣＬＰ后９ｈ）时明显增高，在晚期脓毒症（ＬＳ，ＣＬＰ后１８ｈ）时明显降低。其心肌肌膜蛋白激酶Ｃ（ＰＫＣ）的活性亦呈现类似变化。ＥＳ和ＬＳ大鼠心肌肌膜ＡＣ的增敏和失敏与ＰＫＣ的激活和抑制有关。上述ＡＣ和ＰＫＣ的双相变化不是肾上腺能β－受体和α１－受体系统依赖的。ＥＳ大鼠心肌肌膜ＰＫＣ的激活和ＡＣ的增敏与Ｍ－胆碱受体系统有关；而ＬＳ大鼠心肌肌膜ＰＫＣ的抑制和ＡＣ的失敏与Ｍ－胆碱受体系统无关。

The present work showed that cardiac sarcolemmal (SL) adenylyl cyclase (AC) and purified AC maximal activity of septic rat (eecal ligaation and puncture, CLP)were significantly increased during the early sepsis (ES, CLP 9 h) but decreased in the late sepsis (LS, CLP 18 h). Similar alterations were observed in cardiac sarcolemmal protein kinase C (PKC) activity. Sensitizaion and desensitization of rat SL adenylyl cyclase during ES and LS were respectively correlated with activition and inhibition of PKC. The biphasic changes of AC and PKC were independent of 6β- and α1- adrenergic receptor systems. The rat cardiac sarcolemmal PKC activation and AC sensitization durlug ES is related to M-cholinergic receptor system. The system, however, is not in volved during the LS PKC inhibition and AC desensitization.