DIFFERENTIAL-EFFECTS OF PLATELET DEPLETION ON THE PHYSIOLOGIC ALTERATIONS OF IGE ANAPHYLAXIS AND ACETYL GLYCERYL ETHER PHOSPHORYLCHOLINE INFUSION IN THE RABBIT

Abstract

I.v. administered acetyl glyceryl ether phosphorylcholine (AGEPC) induced all of the respiratory and circulatory alterations observed during IgE anaphylaxis in the rabbit. Prior platelet depletion had differential effects on these 2 physiological responses. The AGEPC-induced increase in total pulmonary resistance and decrease in dynamic compliance were abrogated by prior platelet depletion, whereas these lung mechanical changes occurring as part of an IgE anaphylactic response after i.v. antigen challenge were unaffected by platelet depletion. The apneic episode observed in both the AGEPC and antigen-induced response was unaffected by platelet depletion, and the brief period of rapid shallow breathing of the AGEPC response was diminished to that characteristically seen in the anaphylactic response of both platelet-intact and platelet-depleted rabbits. Prior platelet depletion had little effect on right ventricular hypertension, bradycardia and systemic hypotension of either the AGEPC or the anaphylactic responses. AGEPC induced lung mechanical alterations via platelet-dependent mechanisms, and ventilatory and circulatory alterations by mechanisms largely independent of circulating platelets. AGEPC released into the blood stream during IgE anaphylaxis may mediate the circulatory and ventilatory alterations but not the lung mechanical alterations of the anaphylactic response.