MECHANISM OF CHOLESTEROL ABSORPTION BY THE HYDATID CYSTS OF ECHINOCOCCUS-GRANULOSUS (CESTODA)

The mechanism of cholesterol absorption by hydatid cysts of E. granulosus was studied in function of time of incubation, size of cysts, temperature of incubation, concentration of cholesterol substrate and presence of metabolic inhibitor. The uptake of cholesterol continuously increased with time of incubation. Small cysts absorbed cholesterol better than large ones. The optimum temperature for uptake was 25.degree. C and uptake increased with increase in concentration of substrate. The addition of the metabolic inhibitor 2, 4-dinitrophenol did not affect the process of absorption thus eliminating the participation of the mechanisms of active transport or facilitated diffusion. Mechanisms of simple diffusion and possibly exchange diffusion are probably operating in cholesterol absorption by hydatid cysts.