Monoclonal IgE-mediated cardiac hypersensitivity reactions in the guinea-pig

Isolated heart preparations were prepared from guinea-pigs passively sensitized with mouse anti-DNP monoclonal IgE to study hemodynamic parameters and histamine release upon antigen challenge (DNP-BSA). In the best experimental conditions a triphasic response (increase, decrease, increase) in heart rate and in coronary flow occurred during 10 minutes after challenge. Coronary flow dramatically decreased (50%) at 2.5 min flanked by two periods of increase in flow and tachycardia (+ 55% of the basal heart rate). Contractile force decreased and remained at 80% of its initial value. Histamine is released within 2 minutes after antigen injection. After this period, the observed hemodynamic modifications seem to be due to other anaphylactic mediators such as prostaglandins, leukotrienes and most probably paf-acether.