川芎嗪对糖尿病大鼠血浆内皮素样免疫反应物水平和主动脉舒缩反应的影响

为了探讨糖尿病血管并发病机理及药物防治措施，测定了实验性糖?尿病大鼠血浆内皮素样免疫反应物水平和胸主动脉对内皮素及乙酰胆碱舒?缩反应的变化，并研究了川芎嗪对它的影响. 结果表明：与正常大鼠相比，糖?尿病大鼠血浆内皮素样免疫反应物水平升高（5.1±0.7 ng·L^-1 vs 1.8±0.9 ng·L^-1，P<0.001）；主动脉对内皮素的收缩反应显著增强，对乙酰胆碱舒张反应显著减弱. 川芎嗪不能抑制糖尿病大鼠血糖水平升高，但显著降低血浆内皮素样免疫反应物水平（2.4±0.3 ng·L^-1 vs 5.1±0.7 ng·L^-1，P＜0.001），改善糖尿病大鼠血管内皮依赖的舒缩反应功能.

Effects of tetramethylpyrazine on plasma endothelin-like immunoreactivity level and thoracic aorta contraction and relaxation response in diabetic rats

The effects of tetramethylpyrazine (TMP) on plasma endothelin-like immunoreactivity (ir-ET) levels and the thoracic aorta contraction and relaxation response in diabetic rats induced by streptozocin (STZ) have been studied. The plasma concentration of ir-ET of diabetic rats was significantly increased (5.1±0.7 ng·L^-1 vs 1.8±0.9 ng·L^-1, n=9-10, P<0.001). When aortic rings of the rats were precontracted with KCl (40 mmol·L^-1), ACh induced a concentration-dependent relaxation of the precontracted aorta, and the relaxation response in diabetic rats was significantly lower than that in control rats (P<0.001). The contraction of aorta in response to 100 nmol·L^-1 endothelin-1 was increased markedly in diabetic rats (416±23 mg vs 281±19 mg, P<0.001, n=6). When the diabetic rats were treated with TMP the plasma level of ir-ET was markedly decreased (2.4±0.3 ng·L^-1, vs 5.1±0.7 ng·L^-1, n=12, 10, P<0.001) and the endothelium-dependent vascular function was improved. These results suggest that, 1) the short-term streptozocin treatment may increase the plasma level of ir-ET in rats, while treatment with TMP may markedly decrease the plasma ir-ET in diabetic rats; 2) diabetes may result in a specific impairment of endothelium-dependent relaxation, but enhance the endothelium-dependent contraction; 3) TMP may be of benefit to treat clinical vascular complications of diabetic mellitus.