L-精氨酸对糖尿病大鼠心肌组织钙泵及钠钾泵功能的影响

Effects of L-arginine on the activities of Ca^(2+)-ATPase and Na^+-K^+-AT-Pase in myocardial tissues of diabetic rats

目的 :探讨左旋精氨酸 (L 精氨酸 )对实验性糖尿病大鼠心肌组织钙泵及钠 钾泵功能的影响。方法 :应用链脲佐菌素 (STZ)制备大鼠糖尿病模型 ,随机分为糖尿病模型组、L 精氨酸组、正常对照组 ,用药第 8周末处死动物 ,检测血糖、血中NO含量和NOS活性 ,以及心肌组织的Ca2 + ATP酶、Na+ K+ ATP酶活性 ,分析L 精氨酸对糖尿病大鼠心肌钙泵及钠 钾泵功能的影响。结果 :与模型组比 ,L 精氨酸可以明显降低糖尿病大鼠血糖 ((8.5± 2 .4 )mmol/Lvs (2 5 .8± 4 .3)mmol/L ,P <0 .0 1) ,增加血清中NO含量及NOS活性 (P <0 .0 5 ) ,使心肌组织中的Ca2 + ATP酶及Na+ K+ ATP酶活性明显增加 ((4 6 .5± 3.7) μmol/(mg·h)vs (4 2 .9± 4 .5 ) μmol/(mg·h) ,(2 5 .9± 3.6 ) μmol/(mg·h)vs (18.3± 3.2 ) μmol/(mg·h) ,P <0 .0 5 )。 结论 :糖尿病大鼠心肌存在着钙泵及钠 钾泵功能障碍 ,适当补充外源性L 精氨酸对于改善糖尿病大鼠心肌钙泵及钠

Aim:To study the effects of L arginine on the activities of Ca 2+ ATPase and Na + K + ATPase in myocardial tissues of diabetic rats. Method: The diabetic rats models were made by STZ. Three groups were allocated at random: diabetes group, L arginine group, and normal group. The rats were killed 8 weeks later after using L arginine (250 mg/kg). The blood and myocardial tissues were detected for blood glucose, nitric oxide, nitric oxide synthase activity,and the activities of Ca 2+ ATPase and Na + K + ATPase. Results: L arginine reduced the level of blood glucose ((8.5±2.4)mmol/L vs (25.8±4.3)mmol/L, P <0.01), and increase the content of nitric oxide and nitric oxide synthase activity in serum( P <0.05). The activities of Ca 2+ ATPase and Na + K + ATPase in myocardial tissues were increased in L arginine group compared with that in diabetes group((46.5±3.7)μmol/(mg·h) vs (42.9±4.5)μmol/(mg·h),(25.9± 3.6 )μmol/(mg·h) vs (18.3±3.2)μmol/(mg·h), P <0.05). Conclusion: It is of great value to increase the activities of Ca 2+ ATPase and Na + K + ATPase in myocardial tissues of diabetic rats by giving exogenous L arginine.