Study on therapeutical effect of carbonic acid buffer on rats exposed to phosgene and its mechanisms of oxidation

  Objective   To study the mechanism of pulmonary edema formation and the effect of treatment with carbonic acid buffer on rats exposed to phosgene.

  Methods   40 SD rats were randomly divided into four groups: control group, poisoning group, 0.2 ml carbonic acid buffer group and 0.5 ml carbonic acid buffer group.At the fifth minute the treated groups(0.2 ml group and 05 ml group)were injected with 0.2 or 0.5 ml of carbonic acid buffer by abdominal cavity, respectively.At the third hour, all the rats were killed by decollation.The fluorescence-metry was employed to measure the MDA and GSH.Wet-to-dry weight ratio of rat lung was calculated.

  Results   Compared with the control group, the blood serum MDA level increased(P < 0.01)and GSH content decreased(P < 0.01), the GSSG of liver and the wet-to-dry weight ratio of lung lung increased(P < 0.05)in the poisoning groups.Compared with the poisoning group, the MDA levgel lowed(P < 0.01)and GSH content raised(P < 0.05)in the treated groups, the both changes of the MDA level and GSH content in 0.5 ml carbonic acid buffer group were more significant than those in the 0.2 ml carbonic acid buffer group.The wet-to-dry weight ratio of lung decreased in treated groups, but no significant difference was observed.

  Conclusion   The oxidative stress injury was one of mechanisms of phosegene toxicity in acute poisoned rats.The carbonic acid buffer may have the relieving role on the lung damage in rats exposed to phosgene.