甲基莲心碱对氧自由基介导冠状血管阻力变化的影响

研究了甲基莲心碱（Ｎｅｆ）对氧自由基介导离体大鼠冠状血管阻力变化的影响．结果发现电解性氧自由基可引起冠脉灌注压（ＣＡＰＰ）增加；去冠状血管内皮后，电解所致ＣＡＰＰ的增加明显减弱．预先给予Ｌ－精氨酸（１００μｍｏｌ·Ｌ－１）能明显对抗氧自由基所致的ＣＡＰＰ增加，且Ｌ－精氨酸的作用能部分被硝基－Ｌ－精氨酸（２００μｍｏｌ·Ｌ－１）所对抗，提示电解所致ＣＡＰＰ的增加与氧自由基影响冠状血管内皮功能有关．Ｎｅｆ依剂量性地对抗电解所致ＣＡＰＰ的增加，且Ｎｅｆ（１０μｍｏｌ·Ｌ－１）的作用能被硝基－Ｌ－精氨酸（２００μｍｏｌ·Ｌ－１）或吲哚美辛（１μｍｏｌ·Ｌ－１）所对抗，提示Ｎｅｆ的作用可能部分通过影响前列腺素及内皮源性舒张因子类物质的代谢有关．

Effect of neferine on change of coronary vascular resistance induced by oxygen free radicals in isolated rat hearts

Effect of neferine on change of coronary vascular resistance induced by oxygen free radicals in the isolated rat hearts was studied. Experimental results showed that oxygen free radicals, generated by electrolysis of the physiological perfusate, could induce a progressive increase of coronary perfusion pressure (CAPP) in rat hearts. After removing coronary vascular endothelial cells, the increase of CAPP induced by electrolysis was attenuated significantly. L-Arginine (100 μmol·L^-1), an endogenous nitric oxide precursor, could prevent the CAPP increase elicited by electrolysis, and the effect of L-arginine was partly reduced by N^ω-nitro- L- arginine (200 μmol·L^-1), a nitric oxide synthetase inhibitor. The result suggests that the CAPP increase induced by electrolysis may be associated with the influence of oxygen free radicals on coronary vascular endothelial function. Neferine, a bisbenzylisoquinoline alkaloid, could prevent CAPP increase dose- dependently and the effect of neferine (10 μmol·L^-1) was partly inhibited by N^ω-nitro-L-arginine (200 μmol·L^-1) or indometacin (1 μmol·L^-1). These results indicate that the effect of neferine may be partly related to the metabolism of endothelium-derived relaxing factor or prostaglandin-like substance.