Relationship of non-NO,non-PGI_2 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.