AIM To investigate the effects of chloroquine and dexamethasone on the pulmonary cellular membraneous damages of rats with
smoke inhalation injury. METHODS 100 healthy wistar rats were randomised into control group, five injuried groups at 1 h,3 h,6 h,12 h and 24 h following smoke inhalation, and chloroquine treated groups at 6 h,12 h and dexamethasone treated groups at 6 h,12 h following smoke inhalation. After experiment the rats were killed and the lungs were incised for preparing of
cellular membrane,membraneous lipids were extracted and the compositions phospholipid were detected with high performance liquid chromatography. The fluidity of cellular membrane was measured by fluorescence polarization, and the activities of Na +,K + ATPase and Mg 2+ ATPase and Ca 2+ ATPase were assayed by biochemical method. RESULTS After smoke inhalation the contents of PC,PE,PI in pul monary cellular membrane were significatly declined and simutaneously accompanying by the increases in fluorescence polarization(ρ)and membraneous microviscosity(η) and the decreases in the activities of three kinds of ATPases ( P <0 05～<0 01),while compared with injuried group at 6 h following smoke inhalation chloroquine markedly increased the contents of PC and PE decreased ρ and η, and enhenced the activities of Na +,K + ATPase and Ca 2+ ATPase in group at 6 h following smoke inhalation, but dexamethasone only increased the content of PE, decreased ρ and η, and had no effect on the activities of ATPases. CONCLUSION Smoke inhalation causes the disruption of pulmonary cellular membrane and the decreases in the fluidity of cellular membrane and the activities of ATPases, both chloroquine and dexamethasone partially improve the function of cellular membrane.