Down-regulated CBS/H2S pathway is involved in high-salt-induced hypertension in Dahl rats

Abstract Background The study was designed to explore the significance of endogenous H 2 S in the development of high-salt-induced hypertension in rats. Methods High-salt-induced hypertension rat model was made by feeding Dahl rat high-salt diet containing 8% NaCl for 8 weeks with SD rats as control. SBP and aorta structure in rats were observed. Endogenous H 2 S content and expression of cystathionine β-lyase (CBS), cystathionine γ-lyase and mercaptopyruvate sulfurtransferase in renal tissues were detected. Mechanisms for the impact of high-salt on CBS/H 2 S in renal tissues were studied, targeting HIF-1α pathway. The effect of H 2 S on RAS in serum and renal tissue of rats were tested. Results High-salt reduced endogenous H 2 S content and inhibited the expression of CBS in renal tissue in salt-sensitive Dahl rats. H 2 S donor, however, inhibited salt-sensitive hypertension, reversed aortic structural remodeling and inhibited activation of the RAS system in renal tissues in Dahl rats. Expression of HIF-1α was decreased but expression of PHD2 was increased in renal tissue of Dahl rats with high-salt diet, whereas they did not alter in renal tissue of SD rats with high-salt diet. Ex vivo experiment showed that inhibitor of HIF-1α degradation could rescue down-regulated CBS/H 2 S pathway in renal tissue of Dahl rats with high-salt. In contrast, inhibitor of HIF-1α activity decreased the CBS/H 2 S pathway in the renal tissue of SD rats treated with high-salt. Conclusions Down-regulated CBS/H 2 S pathway in renal tissues under high-salt insult might be an important pathogenesis of salt-sensitive hypertension.