Influence of pH and temperature on hemolysis by adult Schistosoma mansoni membranes.
Membrane fractions from homogenized adult Schistosoma mansoni are known to lyse host red blood cells (RBC's), which serve as an important nutrient source for the parasite. In order to learn more about the hemolytic process, we investigated the effects of pH and temperature on the steps involved in the hemolytic process. For maximum schistosome induced hemolysis to occur the worm lytic agent must be in contact with RBCs in a low pH (pH 5.1), high temperature (37 degrees C) environment for 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 independent and highly concentration dependent. Dose-response experiments suggest that a multi-hit process of hemolysis is probably involved. Temperature 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 approximate pH of the worm gut, appears to be very different.
Kasschau
M R
MR
Program in Biological Sciences, University of Houston-Clear Lake, Texas 77058.
Byam-Smith
M P
MP
Gentry
D S
DS
Watson
F N
FN
D000818:Animals; D006461:Hemolysis / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D009995:Osmosis; D012550:Schistosoma mansoni / Q000502:physiology*; D013696:Temperature