Generation of leukotrienes in guinea-pigs in vivo during antigen-induced bronchospasm.

Anaphylactic bronchoconstriction in passively sensitized guinea-pigs was induced by intravenous injection of antigen (ovalbumin). Five min after injection of the antigen, when the increase in airways resistance to overflow (bronchospasm) was maximum, the plasma levels of leukotrienes LTC4 and LTD4 had increased from undetectable levels of 0.280 and 1.423 ng/ml, respectively. Administration of 5-lipoxygenase inhibitors clearly suppressed the increase in the leukotriene levels concomitant with the suppression of bronchospasm.