RELEASE AND VASOCONSTICTOR EFFECT OF LEUKOTRIENE C-4-LIKE IMMUNOREACTIVE MATERIAL IN THE ANAPHYLACTIC GUINEA-PIG MESENTERIC VASCULAR BED

Antigen challenge of sensitized isolated guinea-pig mesentery perfused under constant pressure resulted in a significant flow reduction, which was paralleled by the release of leukotriene (LT)C4-like immunoreactivity into the perfusates. The lipoxygenase inhibitor quercetin inhibited the release of immunoreactive LTC4 and simultaneously abolished the antigen-induced mesenteric flow reduction. Mesenteric flow reduction was also observed after injection of exogenous LTC4. LTC4 is evidently a constrictor of the mesenteric vascular bed and endogenous LTC4-like immunoreactive material is a mediator of anaphylactic vasoconstriction in the guinea-pig mesentery.