Rat heart anaphylaxis: influence of mediator antagonists

1. Parameters of isolated hearts from rats which were actively sensitized to ovalbumin were found to be impaired on ovalbumin challenge: the heart rate increased whereas the contractility force and coronary flow decreased significantly. 2. Treatment in vivo or in vitro with histamine receptor antagonists (promethacine and cimetidine), the leukotriene antagonist FPL 55712, the PAF antagonist BN 52021, the combined prostaglandin endoperoxide receptor antagonist/thromboxane A2 synthesis inhibitor R 68070, the thromboxane synthetase inhibitor HOE 944, the lipoxygenase inhibitor ZIMET 47/79, the antioxidant sodium hyposulfite or with dexamethasone caused a different improvement of the parameters to a different degree. 3. Consequently, histamine, leukotrienes, PAF, activated oxygen, thomboxane A2 and possibly further autacoids might be involved in mediating the described anaphylactic reaction.