[Experimental study of the effect of dexamethasone on pulmonary diffuse hemorrhage and energy metabolism of mitochondria in the liver of guinea pig infected with leptospirosis].

This experiment was designed to study the curative effect of dexamethasone on leptospirosis with pulmonary diffuse hemorrhage (PDH) in guinea pig model. The guinea pigs were randomly divided into four groups: the infected group, all animals developed PDH(n = 10); the infected plus treated group(n = 10); the treated control group(n = 10); and the normal control group(n = 10). The gross and microscopic observations in lung, liver and kidney were made. Also, ultrastructural changes of mitochondria in liver were examined, and the lactic acid level and mitochondrial ATPase activity in liver were determined. The results showed that there was significant difference in mortality, in gross and microscopic changes in lung, liver and kidney, and in the changes of mitochondrial ultrastructures, ATPase activity and lactic acid level in liver between the infected group and the infected plus treated group (P < 0.01). These findings suggest that the pharmacologic dose of dexamethasone injected intravenously in the early stage of PDH may have some beneficial effect on the emergency treatment of leptospirosis with PDH. The mechanism appears to be related to its effect on the inhibition of glycolysis and increasing oxidative phosphorylation in mitochondria.