Prostaglandin, slow-reacting substance, and histamine release from anaphylactic guinea-pig hearts, and its pharmacological modification

Abstract

Prostaglandins (Pgs), slow-reacting substance of anaphylaxis (SRS-A), and histamine were released from anaphylactic isolated perfused guinea pig hearts. Pgs were to the greatest part of the F_2α-type. PgE₂ was found in traces only. Neither PgA₂, nor the metabolites 13,14-dihydro-15-keto-PgF_2α and 13,14-dihydro-15-keto-PgE₂ were detected in the perfusates. Isoproterenol reduced the PgF_2α output significantly. This effect was increased by the addition of theophylline. Propranolol did not reverse the effect of isoproterenol, but in a high concentration (5 μg/ml) reduced the PgF_2α output for its own. Indomethacin completely abolished the anaphylactic prostaglandin release. The histamine liberation was significantly decreased only by the combination of isoproterenol and theophylline, and also by a high concentration of propranolol (5 μg/ml). In contrast to the Pg release, the anaphylactic SRS-A and histamine liberation was not abolished by indomethacin, but rather increased. The results are discussed in view of the possible role of the released substances in the functional events of cardiac anaphylaxis.