Hydrogen sulfide down-regulation of L-arginine/nitric oxide synthase/NO pathway in aortic tissues of rat / 中国药理学通报

ABSTRACT

Aim To observe the influence of hydrogen sulfide on L-arginine/nitric oxide synthase(NOS)/NO pathway,explore the interaction between H_2S and NO as cardiovascular regulatory gasotransmitters.Methods Aortic thin slices in vitro were administrated with NaHS(10~(-7) mol?L~(-1)～10~(-4) mol?L~(-1)),a donor of H_2S,and incubated for 4 hours,or 50 ?mol?L~(-1) NaHS and incubated for 2 h,4 h and 6 h,respectively.The nitrite production Was measured with greiss assay;NOS activity and L-arginine transportation,with isotope tracer method;the eNOS and CAT1-A gene expression,with RT-PCR.Results After being given with NaHS(50 ?mol?L~(-1)) one time,and incubating for 2 h,the nitrite production decreased by 62%,NOS activity reduced by 48% and L-arginine transport decreased by 50%.After incubation for 6 h,the nitrite production further was inhibited by 19%(P0.05).NaHS(10~(-7) mol?L~(-1)～10~(-4) mol?L~(-1)) inhibited the L-arginine/NOS/NO pathway in a dose-dependent manner,and IC_(50) was 0.499,3.198 and 3.927 ?mol?L~(-1)(P