Summary
Two types of neuraminidase from CL perfringens were injected intravenously in rabbits.
Blood platelet electrophoretic mobility was markedly reduced 4 hours after the injection
of the enzyme. A marked thrombocytopenia developed gradually with a mean lower level
of 55 and 27% of the preinjection number 48 hours after the injec- - tion. White blood
cell count and factors V and VIII were reduced.
The results indicate that rabbit platelets with a reduced surface charge5 due to cleavage of sialic acid from the platelet membrane, are not immediately aggregated,
trapped or destroyed in vivo. We suggest that the enzyme-induced platelet membrane
changes rendered the platelets more susceptible to destruction in the reticuloendothelial
system with appearance of thrombocytopenia after some hours.