INFLUENCE OF PH AND TEMPERATURE ON HEMOLYSIS BY ADULT SCHISTOSOMA-MANSONI MEMBRANES

Membrane fractions from homogenized adult Schistosoma mansoni are know n to lyse host red blood cells (RBC's), which serve as an important nu trient source for the parasite. In order to learn more about the hemol ytic process, we investigated the effects of pH and temperature on the steps involved in the hemolytic process. For maximum schistosome indu ced hemolysis to occur the worm lytic agent must be in contact with RB Cs in a low pH (pH 5.1), high temperature (37 degrees C) environment f or a short time (30 min), after which hemolysis occurs at both pH 7.5 and 5.1.At pH 7.5 the hemolytic process is relatively temperature inde pendent and highly concentration dependent. Dose-response experiments suggest that a multi-hit process of hemolysis is probably involved. Te mperature and dextran experiments suggest that a pore is formed in the RBC membrane at pH 7.5. At pH 5.1 hemolysis is temperature dependent and not very concentration dependent. Dose-response data suggest that a single-hit process of hemolysis is utilized at low pH. The hemolytic process at pH 7.5, the pH of the host blood, and pH 5.1, the approxim ate pH of the worm gut, appears to be very different. (C) 1995 Wiley-L iss, Inc.