Title: Effects of L-Arginine on myocardial ischemia/reperfusion injury of diabetic rats
Abstract: AIM: To observe the effects of L-Arginine (LA) on the changes of angiotensinⅡ (AngⅡ), aldosterone (ALD), insulin-like growth factor-1 (IGF-1), intercellular adhesion molecule-1 (ICAM-1) and free radicals in diabetic rats after myocardial ischemia/reperfusion (MIR). METHODS: The experiment was carried out in the Laboratory of Functional Sciences at Medical School of Jiangsu University from February 2005 to June 2006.①The diabetic model was established by streptozotocin injection to the abdominal cavities of rats. Thirty successful rat models were divided into three groups at random (n =10). MIR group: After thoracotomy and ligation, the rats were injured by ischemia and relaxed 60 minutes later, then reperfusied for 60 minutes; LA group: Four weeks before operation, the rats were injected with 250 mg/kg LA intragastrically, and then received the identical managements as MIR group; Sham group: The treated rats were only braided without ligation and observed for 2 hours. At the end of the experiment, 6 mL ventricular blood was sampled and then rat hearts were excised, remaining myocardium of left ventricle.②The changes of plasma AngⅡ, ALD, serum IGF-1, and ICAM-1 protein expression were evaluated. The contents of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) in serum and myocardial tissues were measured. The activities of Na+,K+-ATPase, Mg2+-ATPase and Ca2+-ATPase in myocardial cytochrome were also detected. RESULTS: All of 30 rats were involved in the result analysis.①Compared with sham group, the levels of AngⅡ and ALD in plasma were increased significantly (P 0.05-0.01) while the levels of serum IGF-1 were decreased in MIR group (P 0.05); The levels of AngⅡ and ALD in plasma were decreased (P 0.05-0.01) while the levels of IGF-1 were increased (P 0.05) in LA group compared with MIR group.②Compared with sham group, the contents of in MDA in serum and myocardium were increased significantly (P 0.05), while the levels of SOD and GSH-PX in serum and myocardium were decreased significantly in MIR group (P 0.05-0.01); The levels of MDA in serum and myocardium were decreased significantly (P 0.05-0.01), while the activities of SOD and GSH-PX in serum and myocardium were increased significantly in LA group compared with MIR group (P 0.05-0.01).③Compared with sham group, the activities of Na+, K+-ATPase, Mg2+-ATPase and Ca2+-ATPase in myocardial cytochrome were decreased significantly in MIR group (P 0.05), but increased significantly in LA group compared with MIR group (P 0.05). Compared with sham group, the expression of ICAM-1 protein in myocardium was increased significantly in MIR group (P 0.01), but decreased significantly in LA group compared with MIR group (P 0.05). CONCLUSION: The AngⅡ, ALD and IGF-1 can participate in MIR-induced injury of diabetic rats. LA has obvious protective effects on the MIR-induced injury, and this action is mediated by the reduction of the expression of ICAM-1 protein. LA ameliorates the myocardial function of diabetic rats probably by scavenging hydroxyl free radicals, decreasing MDA levels, increasing the level of SOD, GSH-PX and ATPase in serum and myocardium.
Publication Year: 2007
Publication Date: 2007-01-01
Language: en
Type: article
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot