Abstract: Objective: To explore the changes of hydrogen sulfide/cystathionine γ-lyase(H2S/CSE) system in rats with insulin resistance and the effect of the H2S/CSE system on the development of hypertension and insulin resistance. Methods: Thirty male Wistar rats were randomly divided into three groups: the normal control(NC) group, the insulin resistant(IR) group and the NaHS(H2S donor)-treated(NaHS) group. The insulin resistant rat model was established by a highglucose diet of 6 weeks. Rats in the NaHS group were subjected to NaHS(56μmol／kg) and rats in the other two groups were subjected to normal saline every day. Six weeks later, the body weight(BW), systolic blood pressure(SBP), fasting blood sugar(FBG), fasting serum insulin(FSI), cholesterin(TC), triglyceride(TG), the transcriptional level of CSE in aorta and the H2S level in plasma were measured, and the insulin sensitive index(ISI) was calculated. Results: Compared with the NC group, BW, SBP, FSI, TC, TG in the other two groups significantly increased (P＜0.01), and the ISI, transcriptional levels of CSE and the H2S levels decreased (P＜0.01). Exogenous administration of NaHS made the transcriptional levels of CSE (P＜0.05) and the H2S levels (P＜0.01) more significantly increased in the NaHS group than in the IR group. Compared with the IR group, SBP in the NaSH group significantly decreased (P＜0.01), but BW, FBG, FSI, TC, TG and ISI did not change a lot. Conclusion: The H2S/CSE system is downregulated in rats with insulin resistance and is a major factor in the development of hypertension. Exogenous administration of H2S may attenuate the process of hypertension, but seems not to affect the insulin sensitive index.

Key words: Insulin resistance, Hypertension, Hydrogen sulfide, Aorta thoracic