Regulation Effects Of Exogenous Hydrogen Sulfide On The Expression Of Pulmonary Surfactant In Rats Of Acute Lung Injury Induced By Paraquat

ObjectiveBy using different doses of exogenous H2S interfering paraquat poisoning rats,and then detecting contests of pulmonary surfactant in rats before and afterintervention,to study the regulation effects of exogenous H2S on the expression ofpulmonary surfactant in rats of acute lung injury induced by Paraquat.Methods60health SD rats (200±20g) were divided randomly into6groups：controlgroup (Group K,injection saline2ml/kg);PQ group (group P, paraquat80mg/kg);PQ+low-dose NaHS group (group L,paraquat80mg/kg+NaHS0.78mg/kg);PQ+middle-dose NaHS group (group M, paraquat80mg/kg+NaHS1.56mg/kg);PQ+high-dose NaHS group(groupH, paraquat80mg/kg+NaHS3.12mg/kg); NaHS group(group N, injection saline2ml/kg+NaHS3.12mg/kg).First,each group was gavaged saline or paraquat as arranged.Three hours later,NaHS and saline were injected. The rats were sacrificed24hours afterparaquat-gavage,and then collected lung tissue and BALF. Lung tissues were slicedfirst, then were observed under optical microscope after HE staining,to assess thepathological changes of lung tissue and IQA. RT-PCR method ware used indeterminating the SP-A、B、C mRNA gene expression,while the content of TP andTPL in BALF were investigated by BCA method and Colorimetric assay. Allexperimental data was recorded for statistical processing. Results1.The pathological changes of lung tissues(1) General view:The appearance of group K was pale pink,smooth surface,without exudation or edema. While group P appeared dark red, obviously congestionand edema, saw a lot of hemorrhage.The lungs of group L looked similar with groupP’s.The exudation and edema in group M and group H made better sequentially thangroup P.The lung tissue of group N looked as well as group K.(2)Microscopic view: The alveolar structure of group K seemed normal. GroupP showed alveolar collapse with structural disordered obviously, a great amount ofinflammatory cells infiltration and lots of red blood cells leaked, alveolar edemaand hyaline membrane could be seen in several alveolar, IQA evidently increased.There was no significant improvement in lung injury of group L compared with groupP, IQA comparison showed no statistical significance; group M, H showed decreasesin lung injury than the P group, IQA lower, but the lung injury still seemed evidentcompared with the group K. The microscopic view of group N and group K lookedsimilar.2.Expression of SP-A、SP-B and SP-C mRNA in lung tissuesIn both of group P and group L, the expressions of SP-A, SP-B and SP-C mRNA weremarkedly lower (P <0.01),compared with group K. M,H group lung tissue’s SP-A,SP-B and SP-C mRNA expression was increased compared with L group (P <0.05); Ngroup lung tissue’s SP-A, SP-B and SP-C mRNA gene expression was consistent withgroup K,comparing the two groups showed no statistical significance.3.Content of TP and TPL in BALFCompared with group K, the content of TP in group P’s BALF significantly increased,while the TPL content decreased obviously. Changes of TP and TPL’s content inBALF of group L was not significant different with group P. In the BALF of group Mand H,the TP content decreased gradually, while the TPL content wentoppositely,compared with group P. Comparing the contents of TP and TPL in BALF of group N with group K showed little difference.Conclusions（1）In the lung of rats with acute lung injury induced by paraquat, the pulmonarysurfactant levels decrease.（2）Exogenous H2S can improve the expressions of pulmonary surfactant inparaquat-poisoning rats, hence reduce lung injury.