Effects Of Hydrogen Sulfide On Pulmonary Surfactant In Acute Lung Injury Induced By Agkistrodon Venom In Rats

ObjectiveTo observe the effect of hydrogen sulfide on pulmonary surfactant in acute lung injuryrat induced by Agkistrodon venom and its possible mechanism on it.Methods1. Grouping:36health adult male SD rats (200±20g), divided into6groups (n=6)randomly： Group I normal saline group;Group II Agkistrodon venomgroup(1.5mg/kg);Group III NaHS low-dose treatment group(Agkistrodon venom+NaHS0.78mg/kg);Group IV NaHS middle-dose treatment group(Agkistrodon venom+NaHS1.56mg/kg);Group V NaHS high-dose treatment group(Agkistrodon venom+NaHS3.12mg/kg);GroupVI CSE inhibitors L-propargylglycine treatment group(Agkistrodonvenom+PPG30mg/kg).2.Method in detail:Saline or Agkistrodon venom were separately administartedinto group I or II with intraperitoneal injection according to the dose above.Thenrespectively injected normal saline,sodium hydrosulfide low,middle,high dose,orL-propargylglycine into I~VI groups after three hours. At six hours after administartion ofsaline or Agkistrodon venom,all rats were put to death and obtain the Bronchoalveolavlavage fluid the lung tissue the experiment need.The histopathologic changes ofHE-staining by light microscopes and a semi-quantitative histological index of quantitativeassessment of lung injury were respectively detected.The surfactant protein A,B,C mRNAgene expression were determinated by RT-PCR.The content of total protein and totalphosopholipids in bronchoalveolar lavage fluid were respectively investigated by BCAmethod and Colorimetric assay.Results1. Changes in histopathology of lung tussue (1)General view:The surface of lung in group I was normal, it was pink and smoothwithout any hemorrhagic foci and edema. The appearance of group II was red withhemorrhagic foci on the surface of the lung tissue，and significantly congestion andedema.The extent of lung injury of Group III~V were ameliorated versus the group II,especicially group V. The appearances of the group VI were severest, with large tracts ofhemorrhagic foci.(2)Endoscopic view:The histopathologic changes by light microscopes and IQA oflung injury: Compared with group I,the intact structure of pulmonary alveoli was destroyedin group II, the alveolar septum was wided, the infiltration of inflammatory cells wereinfiltrated, the alveolar collapse,even the hyaline membrane and atelectasis were also befound,and the grade of IQA increased markedly(P<0.01).Compared with group II, thedegree of lung injury was ameliorated unconspicuously in group III (P>0.05);yet the degreeof lung injury was alleviated in group IV and V,and the grade of IQA increasdsignificantly(P <0.01) while he lung injury of group VI was dramatically exacerbatedcompared with those of other groups and the grade of IQA increasdsignificantly(P<0.01).The extensive hyaline membrane and atelectasis could be found ingroup VI(P<0.01).2.Expression of SP-A, SP-B and SP-C mRNA in lung tissueCompared with group I, group II was markedly decreased, the difference wasstatistically significant(P<0.01);Compared with group II, the expression of SP-A,SP-B andSP-C mRNA in lung tissue were significantly increased in group IV and V(P<0.01),whilethe expression of SP-A,SP-B and SP-C mRNA in lung tissue were unsignificantlyincreased in group III(P>0.05)；Compared with group II, the expression of SP-A,SP-B andSP-C mRNA in lung tissue were significantly decreased in group VI(P<0.05).3.Expression of TP and TPL in BALFThe content of TP was increased and TPL was decreased in BALF in group IIcompared with those of group I (P <0.01). Compared with group II，the content of TP inBALF was significantly decreased in group IV,V (P<0.05), and the content of TPL inBALF was significantly increased in group IV and V (P<0.05). Compared with group II, the contents of TP was significantly increased and TPL was significantly decreased inBALF in group VI (P<0.01).Conclusion1.Expression of SP-A,SP-B and SP-C mRNA was enhanced, the content of TP wasdecreased and the content of TPL in BALF was increased, the index of quantitativeassessment was decreased after administration of NaHS. But administration of PPG couldaggragate ALI.The possible mechanism is that the expression of SP-A,SP-B and SP-CmRNA were decreased,the content of TP was increased and the content of TPL wasdecreased in BALF.2.The possible protective mechanism of H2S in ALI caused by Agkistrodon venommay be the enhancement of the expression of SP-A, SP-B and SP-C mRNA, thedecreasement of TP, the increasement of TPL, and the decreasement of the index ofquantitative assessment.