STUDIES ON HEART ANAPHYLAXIS .I. EFFECT OF ANTIGEN AND HISTAMINE ON GUINEA PIG HEART-LUNG PREPARATION

1. The anaphylactic reaction of the HLP was, with ovalbumin as antigen, studied, and was compared with the effect of histamine on the HLP’s of non sensitized animals. 2. Histamine elicits two forms of heart reactions: (a) an immediate reaction, characterized by heart failure immediately after the injection of histamine and (b) an anoxic heart death occurring later which is elicited by the bronchospasm, but is accelerated by additional mechanisms. 3. The ‘immediate reaction’ occurred only after high histamine doses (2–4 mg histamine dichloride per 20 ml of blood) and could be prevented by mcpyramine. 4. The accelerated anoxic reaction occurred over the whole dose range of 0.02-4 mg. 5. There are at least two factors which accelerate the anoxic death. One is mepyraminc resistant, the other one is mepyramine sensitive. 6. The anaphylactic reaction, too, consists of immediate reaction and an accelerated anoxic heart death. 7. Although in anaphylaxis amounts of histamine are released which correspond to 0.02–0.2 mg of added histamine, none of the anaphylactic reactions of the heart (incl. bronchospasm) could be influenced by mepyramine to a measurable extent. © 1969 S. Karger AG, Basel.