L-精氨酸对离体心肌细胞和心脏微血管内皮细胞一氧化氮合酶活性的影响

目的 :探讨 L-精氨酸对体外培养的心肌细胞和内皮细胞一氧化氮合酶 (NOS)活性的影响。方法 :体外培养 SD大鼠的心肌细胞和心脏微血管内皮细胞 ,72 h后分组 ,实验组在生长液中加入 1 mol/L的 L-精氨酸 ,分别在加入 L-精氨酸后 1 /2、1、2、4h取细胞 ,反复冻融 3次使细胞破裂 ,用分光光度法测细胞内 NOS活性。结果 :加入 1 mol/L的 L-精氨酸后 ,心肌细胞的 NOS活性在 1 /2 h升高至对照组的 1 2 8% (P <0 .0 5) ,2 h时升高至 1 37% (P <0 .0 5) ,4h后下降 ;而内皮细胞在加入 L-精氨酸后 1 /2、1、2、4h时的 NOS活性分别为对照组的 1 2 2 %、1 38%、1 2 8%和1 0 3% ,且内皮细胞 NOS活性较心肌细胞为高。结论 :L-精氨酸可升高心肌细胞和心脏微血管内皮细胞的 NOS活性

Effects of L-arginine on nitric oxide synthase activity of isolated myocytes and cardiac microvascular endothelial cells

Objective:To investigate the effects of L arginine on nitric oxide synthase (NOS) activities of isolated myocytes and endotheliocytes.Method:Cardiac myocytes of neonatal rats and cardiac microvascular endothelial cells of adult rats were isolated and cultured. In the study group, 1 mmol L arginine was added to normal growth medium. Nitric oxide synthase activities were measured at 1/2,1,2 and 4 hours after addition of L arginine.Result:NOS activities of myocytes and endotheliocytes obviously increased at 1/2 h,1 h and 2 h after addition of L arginine, but decreased to basal level at the 4th hour. Endothelial NOS activities were higher than those of myocytes and were more sensitive to L arginine.Conclusion:L arginine can increase the activities of NOS in isolated myocytes and cardiac microvascular endothelial cells.