BIOCHEMICAL STUDY ON THE DIFFERENT PORTAL AND PERIPHERAL SERUM FRACTIONS AND THEIR EFFECT ON THE CELL PROLIFERATION OF S. MANSON/ SCHISTOSOMULES

Abstract

In the present study, schistosomules of Schistosoma mansoni were incubated in vitro in medium containing 10 % fetal calf serum, 10 % portal serum or 10 % peripheral serum together with their fractions separated from highly susceptible hosts (human and hamster) and poorly susceptible host (rat), incubations were performed in presence of bromodeoxyuridine (BrdU) in order to measure differences in cell proliferation. Also the rate of cell proliferation of S. mansoni were assessed in vivo to study the natural ontogeny of the organism. The results showed that portal sera from human and hamster enhanced cell proliferation of schistosomules compared to the peripheral serum. This stimulatory effect was substantially reproduced by a fraction of human portal serum with a molecular weight range between 1-50 kD. While there was no significant difference between portal and peripheral sera separated from rat on cell proliferation of S. mansoni schistosomules. The in vivo results revealed that there was no cell proliferation of S. mansoni schistosomules (6 day old) in the lung. Cell proliferation was detected in schistosomules of 17 day old and the results revealed a significant decrement in the BrdU labeling indices (BLI) with the increase of the age of schistosomules in vivo. The result indicate that portal serum component(s) of a molec.ular weight range (1-50 kD) higher than most simple nutrients separated •from highly• susceptible hosts can greatly stimulate the rate of cell proliferation of S. mansoni schistosomules.