Abstract:Objective To explore the effect of hydrogen sulfide (H2S) on myocardial remodeling in rat model of spontaneously hypertensive rats (SHR). Methods Sixteen 8-week-old male rate were randomly divided into three groups (n?=?8): normal control group, SHR group, and SHR + NaHS group. Rats in SHR+ NaHS group were intraperitoneally injected with sodium sulfide on daily basis (56?μmol/kg) for 8 weeks, while normal saline were administrated in SHR group and WKY group. The content of H2S in peripheral blood and myocardium of rats in each group was determined by spectrophotometry. Pathological changes of myocardium were observed by hematoxylin eosin (HE) staining and Masson trichrome staining. Immunohistochemistry was used to detect the expression of gap junction protein 40, 43 (Cx40, Cx43) in the three groups. Western blotting was used to detect the expression of Cx40, Cx43, smooth muscle actin (α -SMA) and osteopontin (OPN). Results Compared with WKY rats, the content of H2S in peripheral blood and myocardium of SHR group decreased (P?0.05), which was restored with treatment of NaHS (P?0.05). Compared with the WKY group, rats in SHR group experienced disordered myocardial fiber structure, which were normalized with NaHS intervention. IHC results showed that the expression of Cx40, Cx43 in myocardium of SHR group was increased though distributed disorderly. The distribution of Cx40, Cx43 in myocardium of SHR + NaHS group is more regular than that of SHR group. Western blotting analysis showed that the expression of Cx40, Cx43, α-SMA, OPN in SHR group was increased when compared with those in WKY group (P?0.05), which was reversed in SHR+NaHS group (P?0.05). Conclusions H2S may reverse SHR induced myocardial remodeling through mediation of Cx40 and Cx43.