Effects of haemolysins of groups A and B streptococci on cardiovascular system.

Anaesthetized New Zealand white rabbits and rats were either injected or infused with streptolysin S and group B streptococcal haemolysins in order to observe the haemodynamic actions of these haemolysins. Results showed that streptolysin S had little or no effect. In contrast, group B streptococcal haemolysin showed significant hypotensive action as manifested in rapid reduction of systolic, mean, diastolic and pulse pressures, and a limited number of deaths due to shock.