The Adjusting Effect Of Hydrogen Sulfide On Oxidative Stress In Rat’s Acute Lung Injury Induced By Paraquat

Objective:Observe the change of protection and damage oxidative index in rat’s acute lunginjury induced by paraquat when increase body’s level of H2S, to explore the H2S/CSE system adjusting effect on oxidative stress in rat’s acute lung injury induced byparaquat.Methods:Choose sixty healthy and clean Sprague Dawley (SD) rats which were randomlydivided into six groups, and each group were ten rats: normal saline control group(group N), sodium hydrosulphide control group (group NaHS), paraquat poisoninggroup(group PQ), paraquat+low-dose NaHS group (group L), paraquat+dose NaHSgroup group (group M), paraquat+high-dose NaHS group (group H). Group L,M, Hand group PQ were lavaged with paraquat dose of80mg/kg, and group L, M, H wererespectively imparted NaHS0.78mg/kg,1.56mg/kg,3.12mg/kg by intraperitonealinjection in three hours after paraquat lavage,While group PQ was imparted normalsaline2ml/kg by intraperitoneal injection. Group N and group NaHS were lavagedwith normal saline2ml/kg,3hours later group N was imparted saline solution2ml/kg by intraperitoneal injection, and group NaHS were imparted sodiumhydrosulphide3.12mg/kg by intraperitoneal injection. All experimental rats weresacrificed by abdominal aorta bleeding at24hours after intragastric administra-tion. Adopting the method of removaling protein was used to test the content of H2Sin plasma; Observation the change of lung wet/dry weight ratio; Take the right lowerlung tissue to hematoxylin-eosin staining, observed the changes of histopathologicalunder the light microscopy; Testing the activity of GSH-Px,SOD and the contents ofMDA in lung tissue homogenate; The activity of CSE in lung tissue homogenatewas was evaluated by methylene blue method. Results:(1) There is no obviously difference between group N and group NaHS inhistopathological and lung injury score, and they have no lung injury expression. Ingroup PQ the structure of lung tissue have a visible damage, a large number ofalveolar interval fracture and mutual confluence, a large amount of red blood cellsleaked in the alveolar cavity, and pulmonary interstitial was infiltrated by lots ofneutrophils, lung injury pathological score increased significantly compared withgroup N (P <0.01). Compared with Group PQ, the degree of pulmonary injury is notimproved remarkably in Group L and had no statistical significance (P>0.05), whilethe degree of pulmonary injury were ameliorated markedly in group M and group H,lung injury pathological score decreased obviously (P <0.01).(2) Group N and group NaHS have no significant difference on the lung wet/dryweight ratio (P>0.05); Compared with group N, the lung wet/dry weight ratio ofgroup PQ increased significantly (P <0.01); Compared with the group PQ, the lungwet/dry weight ratio of group L did not obviously decreased and had no statisticalsignificance (P>0.05), while the lung wet/dry weight ratio of group M and group Hwere reduced dramatically compared with group PQ (P <0.01).(3) Compared with group N, the level of H2S in plasma and the activity of CSEin lung tissue homogenate were evidently decreased in group PQ (P <0.01);Compared with group PQ, the level of H2S in plasma and the activity of CSE in lungtissue homogenate were not obviously improved in group L(P>0.05), while the levelof H2S in plasma and the activity of CSE in lung tissue homogenate were significantlyincreased in group M and group H (P <0.01).(4) Compared with group N, the activity of GSH-Px and SOD in lung tissuehomogenate were significantly descended in group PQ (P <0.01); Compared withgroup PQ, the activity of GSH-Px and SOD in lung tissue homogenate were notsignificantly increased in group L (P>0.05), while the activity of GSH-Px and SODin lung tissue homogenate were significantly increased in group M and group H (P <0.01). (5) Compared with group N, the content of MDA in lung tissue homogenate wasobviously increased in group PQ (P <0.01); Compared with group PQ, the content ofMDA in lung tissue homogenate were not signally decreased in group L (P>0.05),while the content of MDA in lung tissue homogenate were signally decreased ingroup M and group H (P <0.01).Conclusions(1) The activity of GSH-Px and SOD were decreased and the contents of MDAwere increased in lung tissue homogenate of rats infected by paraquat.(2) After added exogenous NaHS, in lung tissue homogenate of rats infected byparaquat the activity of GSH-Px and SOD were elevated and the contents of MDAwere lowered, the ability of NaHS on the improvement of the acute lung injury is dosedependent.