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目的探讨茶提取物茶多酚和茶黄素预防离体大鼠血管对硝酸甘油耐受的作用。方法用硝酸甘油30μM预孵90min的方法诱导大鼠离体胸主动脉环对硝酸甘油产生耐受,用苯肾上腺素预收缩血管,通过organbath的方法观察茶提取物茶多酚和茶黄素处理与否对硝酸甘油舒张血管作用的影响。结果硝酸甘油预孵使血管对硝酸甘油的舒张反应显著减弱,pD2由对照组的8.21±0.09降低为耐受组的6.86±0.20(P<0.05);茶多酚和茶黄素预处理均使硝酸甘油耐受血管的舒张反应明显增强,pD2值分别为7.76±0.11和7.97±0.13,与耐受组相比均P<0.05;各组Emax无显著变化。结论茶多酚和茶黄素预处理可预防离体大鼠血管发生硝酸甘油耐受。
Objective To investigate the effects of tea polyphenols and theaflavins on the tolerance of isolated rat blood vessels to nitroglycerin. Methods Preincubation of rat thoracic aorta ring with 30μM nitroglycerin for 90min induced tolerance to nitroglycerin, pre-constricted blood vessels with phenylephrine, and organophthalmic extracts of tea polyphenols and theaflavins were observed by organbath Effect of Nitroglycerin on Vasodilatation. Results Preincubation of nitroglycerin significantly attenuated the vasorelaxation of nitroglycerin in the blood vessel, and the pD2 decreased from 8.21 ± 0.09 in the control group to 6.86 ± 0.20 in the tolerated group (P <0.05). Pretreatment with both tea polyphenols and theaflavins The vasodilatory responses to nitroglycerin-resistant vessels were significantly enhanced with pD2 values of 7.76 ± 0.11 and 7.97 ± 0.13, respectively, compared with those of the tolerated group (P <0.05). There was no significant change of Emax in each group. Conclusion Pretreatment with tea polyphenols and theaflavins can prevent nitroglycerin tolerance in isolated rat blood vessels.