[Biochemistry of schistosomiasis mansoni. VII. Lipid changes of lysosomal membranes during the initial phase of liver injury].

Aiming at investigating the changes on the lipidic constitution of hepatic lysosomal membranes at the initial phase of schistosomatic damage, mice have been infected with 30 cercarias and employed for essais in the 30th day of infection. The triacylglycerois decreased from 220 +/- 48 micrograms/mg of total proteins in the control mice, to 165 +/- 22 micrograms/mg in the infected ones. Similarly, the free cholesterol, also decreased from 539 +/- 80 to 396 +/- 54 micrograms/mg; the cholesterol esters from 270 +/- 35 to 216 +/- 36 micrograms/mg and the phosphatidylcholines from 44 +/- 5.7 to 31 +/- 4.9 micrograms/mg. The phosphatidylserines the phosphatidylethanolamines and the sphingomyelins increased, respectively from 58 +/- 9.7 to 60 +/- 8.5, from 72 +/- 7.8 to 111 +/- 15.7 and from 36 +/- 4.9 to 63 +/- 7.1 micrograms/mg. The free fatty acids showed no statistical significance on their variations. They varied from 1.7 +/- 0.25 microEq/g in the controls to 1.8 +/- 0.39 microEq/g in the infected animals. These results indicated that in the initial phase of hepatic schistosomiasis, before the formation of granulomas, important changes on the lipidic constitution of lysosomal membranes can be detected. It seems that they are provoked by the catabolic excreted by immature or adult worms of Schistosoma mansoni present in the portal vein system.