Leukotriene D4 potentiates histamine-induced bronchoconstriction in guinea-pigs

Abstract

Histamine concentration-response curves performed on isolated airways smooth muscle preparations were unaffected by threshold constrictor concentrations of LTD4 (194±34 p M for parenchymal strips and 1940±480 p M for isolated trachea, respectively). In contrast, LTD4, when administered between 2 and 60 s beforehand, potentiated bronchoconstrictor responses to histamine in anaesthetized, artificially ventilated guinea-pigs. Doses of LTD4, which did not produce direct effects on airways resistance, potentiated histamine-induced bronchoconstriction to a lesser degree than those having small direct effects. This potentiation was prevented by bilateral vagotomy. In addition, the antagonists atrop..