Down-regulation of glutamyl cysteine cystathionine-lyase/hydrogen sulfide system in rat cardiovascular calcification

AIM：To observe the changes of cystathionine-lyase/hydrogen sulfide (CSE/H2S) in vivo in vascular calcification and to explore the role of CSE/H2S in vascular calcification.METHODS：Vascular calcification model in rats was induced by administration of vitamin D3 plus nicotine.The extent of calcification was estimated by assaying calcium content.［45Ca2+］ deposition and alkaline phosphatase (ALP) activity were detected.CSE mRNA amount was determined by using competitive quantitative RT-PCR.The content of H2S and activity of CSE in the plasma and cardiovascular tissues were also determined with biochemical methods.RESULTS：Calcium content in myocardium increased by 3.8 folds in a calcification model.Compared to control,calcium content,［45Ca2+］ accumulation and ALP activity in calcified arteries increased by 6.8,1.4,and 1.9 folds,respectively (P＜0.01).H2S contents in plasma,myocardium and aorta were 39%,39% and 31% lower than those in control group (P＜0.01).The gene expression of CSE was down-regulated in myocardium and aorta.Compared to control group,the amount of CSE mRNA in myocardium and calcified aorta were decreased by 28% and 36%,respectively (P＜0.01).The activity of CSE was 56% and 53% lower than that in control (P<0.01).CONCLUSION：The production of H2S,the gene expression and activity of CSE are down-regulated in the cardiovascular calcification,suggesting that the decrease in H2S production plays a role in the pathogenesis of vascular calcification.