Generation of a leukotriene-like substance from porcine vascular and other tissues.

When chopped porcine vascular tissue was incubated with A23187 in the presence of a cyclo-oxygenase inhibitor, a substance with the biological properties of a leukotriene was released into the supernatant. The highest concentrations of leukotriene-like material were released by coronary and pulmonary arteries and the adventitia removed from these vessels, the greatest amount being released by the adventitia. Smaller quantities of leukotriene-like substance were released from other blood vessels but not from aorta, atrial or ventricular smooth muscle. Release of the leukotriene-like material was time-dependent. The activity of the leukotriene-like substance was antagonised by FPL 55712 and its release was inhibited by BW 755c. Leukotriene-like material was also generated from guinea-pig, rat, rabbit and dog blood vessels incubated with A23187 and from guinea-pig vessels during antigen challenge.