辛伐他汀对糖尿病大鼠阿司匹林抵抗的影响及其机制

目的：观察辛伐他汀对糖尿病大鼠阿司匹林抵抗的作用及机制。方法：选取雄性8周龄Wistar大鼠96只,随机分成糖尿病组和正常组（n=48）。糖尿病组大鼠腹腔一次性注射1%链脲佐菌素（STZ） （65 mg/kg,溶于0.l mmol/L、pH 4.5的柠檬酸缓冲液）来诱发糖尿病模型,正常组大鼠注射相同剂量的柠檬酸缓冲液。血糖大于16.8 mmol/L且同时具备多饮、多尿、体重减轻的糖尿病症状的大鼠认为糖尿病造模成功。糖尿病和正常大鼠分别随机分为糖尿病对照组（DM）、糖尿病阿司匹林组（DM-ASA）、糖尿病辛伐他汀组（DM-SIM）、糖尿病阿司匹林联合辛伐他汀组（DM-ASA+SIM）和正常对照组（NC）、正常阿司匹林组（NC-ASA）、正常辛伐他汀组（NC-SIM）、正常阿司匹林联合辛伐他汀组（NC-ASA+SIM）（n=12）。阿司匹林组、辛伐他汀组及阿司匹林联合辛伐他汀组分别给予10 mg/kg阿司匹林、2 mg/kg辛伐他汀、10 mg/kg阿司匹林加2 mg/kg辛伐他汀溶于PBS灌胃,对照组给予等量PBS灌胃。连续灌胃8周后,评价血小板聚集功能和血小板活化指标,检测大鼠血清一氧化氮（NO）、内皮素（ET）、前列环素（PGI2）、脂联素（APN）、血栓素B2（TXB2）水平和血清超氧化物歧化酶（SOD）、丙二醛（MDA）水平;进行大鼠胸主动脉离体血管张力实验评价内皮功能;检测大鼠胸主动脉血红素氧合酶-1（HO-1）、血红素氧合酶-2（HO-2）、内皮型NO合酶（eNOS）、磷酸化-内皮型NO合酶（p-eNOS）、抗凋亡蛋白（Bcl-2）、环加氧酶-2 （COX-2）等蛋白的表达水平。结果：与对照组大鼠相比,糖尿病大鼠其血小板活化及聚集值增高,且模型组呈现阿司匹林的反应性减低现象（P<0.05）;在糖尿病大鼠,阿司匹林联合辛伐他汀较单用阿司匹林组显著降低血小板活化及聚集值（P<0.05）,其通过上调HO-1、eNOS、p-eNOS、Bcl-2等蛋白的表达水平及升高血清APN水平,下调COX-2蛋白表达水平,通过改善内皮功能,调节TXA2/PGI2水平、增加NO水平,发挥其抗血小板作用。结论：糖尿病大鼠呈现阿司匹林反应性减低,辛伐他汀具有潜在的改善血小板对阿司匹林的反应性的作用。

The experimental study of simvastatin on improving aspirin resistance in diabetic rats

Objective: The purpose of the present study was to investigate the effects of the combination of aspirin, simvastatin in diabetic rat on platelet function.Methods: Eight-week-old male Wistar rats were selected and randomly divided into diabetic group (n=48) and normal control group (n=48). Diabetic rats were injected with 1% STZ (65mg/kg, dissolved in 0.l mmol/L, pH 4.5 citrate buffer) to induce diabetic model and the rats in normal control group were injected with the same dose of citrate buffer. A rat with blood glucose greater than 16.8 mmol/L and along with diabetic symptoms of polydipsia, polyuria and weight loss was considered the successful model of diabetes. Diabetic rats and normal Wistar rats were randomly divided into 4 groups and given aspirin(10 mg/kg), simvastatin(2 mg/kg), combination of aspirin(10mg/kg) and simvastatin(2 mg/kg), PBS for 8 weeks, respectively. The platelet function and the expression of CD62P were evaluated. The levels of nitric oxide (NO), endothelin (ET), thromboxane B2(TXB2), prostacyclin (PGI2), adiponectin (APN), TXB2 were detected in the serum. The expressions of heme oxygenase-1(HO-1), HO-2, endothelial nitric oxide synthase(e-NOS), p-eNOS, B-cell lymphoma-2(Bcl-2), cyclooxygenase-2(COX-2) in thoracic aorta were evaluated by Western blot.Results: Compared with control rats, diabetic rats had high platelet aggregation and activation (P<0.05), which treated aspirin also showed lower aspirin sensitivity (P<0.05). The combination of drugs upregulated the expression of HO-1, eNOS, p-eNOS, BCL-2, APN levels and decreased the expression of COX-2, and had a greater inhibitory effect on platelet aggregation and activation. The combination of drugs improved endothelial function, adjusted TXA2/PGI2 levels and increased NO levels, which resulted in a great potential antiplatelet effect.Conclusion: These results suggest that simvastatin may improvethe effect of aspirin on anti-platelet function in diabetic rats.