非NO、非PGI2介导大鼠大脑中动脉舒张反应与硫化氢的关系

目的 研究硫化氢(H2S)与非一氧化氮(NO)、非前列环素(PGI2)介导的大鼠大脑中动脉(MCA)舒张反应的关系.方法 采用离体微血管舒缩功能测定大鼠大脑中动脉舒张功能.结果 在U46619预收缩的大鼠大脑中动脉上,10-7~10-4.5mol·L-1的ACh可显著诱导大鼠大脑中动脉呈浓度依赖性舒张,但血管用NO合酶抑制剂L NAME(3×10- 5 mol·L-1)和PGI2合成抑制剂Indo (1×10- 5 mol·L-1)预处理后,ACh的舒张反应有明显的减弱,最大舒张率由78.2%±4.6%降至56.5%±4.0%,并且剩留舒张反应几乎可被内源性H2S合成酶抑制剂PPG(10-4mol·L-1)完全取消.H2S供体NaHS在10- 5~10-2.5mol·L-1范围内对U46619预收缩的大鼠大脑中动脉也呈一定的浓度依赖性舒张作用.结论 非NO、非PGI2介导的大鼠大脑中动脉舒张反应与H2S有关.

Relationship of non-NO,non-PGI2 mediated relaxant effects with hydrogen sulfide in rat middle cerebral artery

Objective To study relationship of non-NO,non-PGI2 mediated relaxant effects with hydrogen sulfide(H2S) in rat middle cerebral artery.Methods The relaxant effect of isolated rat middle cerebral artery was detected by vasomotoricity experiment in vitro.Results In isolated rat middle cerebral artery that precontracted with U46619,ACh(10-7 ~ 10-4.5) had a concentration-dependent relaxation.The ACh-induced vasorelaxation was significantly inhibited in the presence of 3×10-5mol·L-1 L-NAME and 1×10-5 mol·L-1 Indo,and the maximum diastolic ratio dropped from 78.2%±4.6% to 56.5%±4.0%,and the left relaxation was almost abolished by 10-4mol·L-1 PPG.NaHS,a donor of H2S,at the range of 10-5 ~ 10-2.5mol·L-1,had the concentration-dependent relaxation.Conclusion H2S is involved in the non-NO,non-PGI2 mediated relaxant effects in rat middle cerebral artery.