败血症休克时心肌肌浆网Ryanodine受体的变化及其机制研究  

ALTERED RYANODINE RECEPTOR OF RAT CARDIAC SARCOPLASMIC RETICULUM AND ITS UNDERLYING MECHANISM DUING SEPTIC SHOCK

作　　者：董林旺[1] 吉勇[1] 王雪青[1] 吴立玲[1] 唐朝枢[1] 

机构地区：[1]北京医科大学心血管基础研究所休克研究室

出　　处：《生理学报》1995年第4期349-356,共8页Acta Physiologica Sinica

摘　　要：本文观察了败血症休克时心肌终囊处肌浆网（ＳＲ）钙释放通道Ｒｙａｎｏｄｉｎｅ受体的变化及其膜脂质微环境改变的机制。结果发现，晚期败血症休克大鼠心肌肌浆网（ＣＳＲ）Ｒｙａｎｏｄｉｎｅ与受体结合的Ｂｍａｘ降低４１．３％（Ｐ＜０．０１），Ｋｄ值无明显变化。钙离子可明显激活３Ｈ－Ｒｙａｎｏｄｉｎｅ与其受体的结合，其激活曲线在钙离子浓度为５×１０－５ｍｏｌ／Ｌ时达到饱和状态。咖啡因，ＡＴＰ，ＡＭＰ－ＰＣＰ都可浓度依赖性地促进３Ｈ－Ｒｙａｎｏｕｉｎｅ与受体的结合，而钌红（ＲｅｔｈｅｎｉｕｍＲｅｄ），氯化镁则浓度依赖性地抑制其结合。但败血症休克时上述激动剂或抑制剂的Ａ０．５和ＩＣ５０均无明显改变。用磷脂酶Ａ２消化假手术动物ＳＲ后，其３Ｈ－Ｒｙａｎｏｄｉｎｅ与受体的结合明显降低，将磷脂酰胆碱（ＰＣ），磷脂酰乙醇胺（ＰＥ）和磷脂酰丝氨酸（ＰＳ）分别参入到上述消化后的ＣＳＲ膜中可明显提高３Ｈ－Ｒｙａｎ－ｏｄｉｎｅ与受体的结合。同时，ＰＣ，ＰＥ，ＰＳ分别参入ＣＳＲ中可显著改善败血症休克时ＣＳＲ３Ｈ－Ｒｒａｎ－ｏｄｉｎｅ与受体的低结合状态。上述结果表明，败血症休克时，内毒素抑制大鼠ＣＳＲ３Ｈ－Ｒｙａｎｏｄｉｎｅ受体结合与其过度激活磷?The present study was undertaken to observe the changes of Ryanodine receptor of cardiac junctional sarcoplasmic reticulum (SR) in relation to membrane lipid microenvironment alteration during septic shock. The results showed that the Bmax for 3H-ryanodine binding to cardiac junctional SR was decreased by 41. 3 % (3. 9± 0. 1 vs. sham 6. 6 ± 0. 7 pmol/mg, P<0. 01 ) while the Kd value was unaffected during late septic shock (CLP 18 h). Ca2+ activated 3H-ryanodine binding significantly and reached a saturation value when Ca2+ concentration was 5 × 10-5 mol/L, while the S0. 5 and the Hill coefficient values remained unchanged during septic shock. Caffeine, ATP, and AMPPCP activated while Mg2+, ruthenium red inhibited 3H-ryanodine binding in both groups but the A0. 5 (concentration requires for half maximum activation) and the IC50(concentraion requires for half-maximum inhibition) for the above mentioned activators and inhibitors, were respectively unaffected during septic shock. Digestion of cardiac SR isolated from control rats with phospholipase A2 inhibited 3H-ryanodine binding,which could be dramatically recovered by the incorporation of phosphatidylcholine (PC), or phosphatidylserine (PS), or phosphatidylethan clam me (PE ) into the isolated cardiac SR. Incorporation of above phospolipids into SR isolated from septic rats reversed shock-induced inhibition of 3H-ryanodine binding. It is concluded that the mechanism responsible for the inhibition of 3H-ryanodine binding of junctional SR duing septic shock may be related to modification of membrane lipid microenviroment in response to PLA2 overactivation during septic shock.

关 键 词：败血症 休克 RYANODINE受体 心肌 肌浆网 

分 类 号：R631.402[医药卫生—外科学]