Biological activities of enterotoxin from Vibrio cholerae non-01

The specific antiserum 54(2) prepared in rabbits by combined intraperitoneal and intravenous immunization with the enterotoxin from Vibrio cholerae non-01 was found to neutralize the enterotoxin biologic activity expressed by rabbit skin vascular permeability and hemorrhage factors. The inhibition of biologic activity was also observed when using antiserum to choleragen, but choleragen could not be neutralized by specific serum 54(2). The enterotoxin was also inactivated when heated at 100 degrees C for 10 min, but heating at 56 degrees C for 30 min had no influence on its biologic activity. The enterotoxin from Vibrio cholerae non-01 was found to elevate concentration levels of cAMP in the epithelial cells of the rabbit intestine and this elevation was comparable with that produced by the filtrate of Vibrio cholerae 569 B culture. The culture filtrate from Vibrio cholerae non-01 exhibited a similar activity. The Vibrio cholerae non-01 enterotoxin as well as the original culture filtrate were found to be cytotoxic for Vero cells.