Characterization and modulation of antigen-induced effects in isolated rat heart.

The response to antigen (trinitro-phenyl-haptenized ovalbumin) and the modulatory role of several antiallergic drugs was studied in isolated hearts from actively sensitized rats. Antigen induced a triphasic effect on coronary flow (CF) and left ventricular pressure (LVP) characterized by short-term increase (0-1.5 min=phase 1) and a severe decrease (1.5-7.5 min=phase 2) followed by a less pronounced long-lasting decrease (7.5->20 min=phase 3). The first phase was accompanied with a substantial release of 5-hydroxytryptamine (5-HT), histamine, and leukotrienes measured in cardiac effluents