Effect of experimental schistosomiasis on 14C-4-cholesterol esterification by mouse liver homogenate.

The effect of experimental schistosomiasis mansoni on cholesterol esterification by mouse liver homogenate was studied using 14C-4-cholesterol. The reaction was carried out in 0.85 ml containing 10 nCi labelled cholesterol (164 nmol as an albumin-stabilized emulsion) with 30 mg tissue homogenate in 176 mM sodium phosphate buffer, pH 7.1, containing 59 microM oleic acid, 0.3 mM CoASH and 8.8 mM ATP. In experiments with liver from infected mice (N = 22), the percentage of cholesterol esterification was 6.9 +/- 0.7%/h. This rate was 52% less than that observed in normal mice (14.4 +/- 0.6%/h, N = 21). The decrease may be due to the existence of inhibitors of the cholesterol esterifying in the infected liver, increased hydrolysis of cholesteryl esters or a decrease in the synthesis of the enzyme acyl CoA:cholesterol acyl transferase by the infected liver.