Effects Of Hypoxia And Hypoxic Training On Hydrogen Sulfide Generation In Skeletal Muscle Of Rats

1 ObjectivePick up the best assay method applying for measuring the endogenous levels of H2S and H2S synthetase activity of skeletal muscle in rats from two methods which can measure the endogenous levels of H2S and its synthetase activity at present;Measure the endogenous levels of H2S and H2S synthetase activity of skeletal muscle in rats after hypoxic training, analyze the change characteristics of them,and discuss the possible mechanism of H2S/ synthetase system impact on the change of skeletal muscle function after hypoxic training.2 MethodsExperiment with male Sprague-Dawley rats,the endogenous levels of H2S and H2S syntbetase activity of skeletal muscle in rats were measured by methylene blue colorimetry and sensitive sulphur electrode respectively.Compare and analysis of the results.24 male Sprague-Dawley rats were divided into four groups randomly, normoxic control groups(NC),normoxic training groups(NT),hypoxic controls groups(HC) and hypoxic training groups(HT).NC and NT groups rats were bred in normal environments,HC and HT groups rats were bred under hypoxic condition which simulated 4000 meters altitude(oxygen concentration was about 12.7%).NT and HT groups rats were performed treadmill running training on a motor-driven treadmill once daily and S days a week,4 weeks total.The running velocity was 20m/min,the inclination of the treadmill was 10°,the first training duration was 10min,and followed increases to 60min.After the last training day,left gastrocnemius in all groups rats were extracted,then the endogenous levels of H2S and H2S synthetase activity of gastrocnemius were measured by sensitive sulphur electrode. 3 Results3.1 Methylene blue colorimetry fail to assay the levels of H2S of skeletal muscle in rats,the H2S synthetase activity measured by methylene blue colorimetry was lower than that measured by sensitive sulphur electrod significantly(P＜0.01);the recovery rate of sensitive sulphur electrod was high,both the repeatability and stability were fine.3.2 After 4 weeks training,compared with NC group,the weights of NT,HC and HT groups rats were all decreased,those of HT group rats decreased most significantly(HT＜NT＜HC＜NC)3.3 After 4 weeks training,the levels of H2S of skeletal muscle in rats of NT group was lower than those of NC group;those of HT group increased when compared with HC group;those of HI group increased when compared with NT group;those of HC group decreased when compared with NC group.But significant difference was not found.3.4 After 4 weeks training,compared with the control groups,the H2S synthetase activity of skeletal muscle in training groups rats were all decreased.Those of NT group decreased when compared with NC group; those of HI group decreased when compared with HC group;those of HC group and HT group were lower than those of NC group and NT group respectively; those of HI group was lower than those of NC group significantly(P＜0.05).4 Conclusions4.1 Methylene blue colorimetry was not apply for the research of H2S and its synthetase of skeletal muscle in rats;the measure scope of sensitive sulphur electrode was wide,sensitivity,stability and repeatability were fine,so it could be used for the research of H2S and its synthetase of skeletal muscle in rats.4.2 Chronic hypoxia and exercise training could make the H2S/synthetase system down.We guess that H2S/synthetase system may mediate the regulate mechanism of capillaries hyperplasia and aerobic oxidase activity increasing of skeletal muscle after hypoxic training.4.3 Normoxic training may decrease the levels of H2S by inhibiting the H2S synthetase activity.4.4 The levels of H2S and its synthetase of skeletal muscle in hypoxic training group rats changed in the opposite,it may had something with that the H2S synthetase activity was negative feedback regulated by the levels of H2S.4.5 After 4 weeks training,the levels of H2S of skeletal muscle in HT group rats was higher than those of NT group and HC group,lower than those of NC group;the H2S synthetase activity was lower than those of NT group and HC group,lower than those of NC group significantly.It indicated that the effects of chronic hypoxia and exercise training were not together simply.