Change of endogenous hydrogen sulfide/cystathionine-γ-lyase system in acute lung injury induced by LPS in rats

AIM: To observe the changes of endogenous hydrogen sulfide/cystathionine-γ-lyase(H2S/CSE) system while acute lung injury induced by LPS in rats.METHODS: Eighty rats were randomly divided into six groups(n=8): Ⅰ,control group;Ⅱ,LPS 1 h group;Ⅲ,LPS 3 h group;Ⅳ,LPS 6 h group;Ⅴ,LPS 9 h group;Ⅵ,LPS 12 h group.The ALI model of rats was prepared with LPS.The rats were respectively killed at 1,3,6,9 or 12 h after administration of LPS.The morphological changes of lung tissues were observed by light and electron microscope.The lung coefficient and the wet-to-dry weight ratio were measured.The contents of IL-1β and IL-10 in serum,the H2S level in plasma and the CSE activity in lung tissue were respectively detected.RESULTS: ⑴ In LPS 1 h group,the morphology,the lung coefficient,the wet-to-dry weight ratio,the H2S level and the CSE activity showed no changes compared with the control group.The contents of IL-1β and IL-10 were increased compared with the control group(IL-1β,P0.05;IL-10,P0.01).⑵ In LPS 3 h,6 h,9 h and 12 h groups,compared with the control group,the lung tissues were significantly damaged,the lung coefficient and the wet-to-dry weight ratio were significantly increased respectively(LPS 3 h,P0.05; LPS 6 h,9 h,12 h,P0.01).The contents of IL-1β and IL-10 in serum were markedly increased(P0.01).The H2S level in plasma and the CSE activity in lung tissue were significantly decreased(P0.01).CONCLUSION: The changes of inflammatory cytokines may be the pathological foundation of the ALI induced by LPS and the endogenous hydrogen sulfide/cystathionineγ-lyase system is possibly involved in the formation of the ALI.