AN ANALYSIS OF THE TOXIC ACTIONS OF PURIFIED STREPTOLYSIN O ON THE ISOLATED HEART AND SEPARATE CARDIAC TISSUES OF THE GUINEA PIG

Abstract
The response of isolated guinea pig hearts to perfusion with purified streptolysin O is characterized by a rapid, but transient, decrease in rate and amplitude of contraction; these reactions are superimposed upon a gradual, irreversible, loss of ventricular contractility. At ventricular standstill, the atria continue to beat spontaneously in a normal way. Isolated ventricle strips prepared from such preparations can be driven electrically, and their behavior is functionally indistinguishable from that of similar preparations made from normal hearts.