Abstract
Contraction of passively sensitized human bronchus induced by antigen challenge in vitro, was reduced by the prostaglandin F synthetase inhibitor, indomethacin. Prostaglandin F was released during challenge and this release was inhibited by indomethacin. There was a significant correlation between prostaglandin F release and antigen challenge‐induced contraction, suggesting that this substance may contribute to the bronchoconstrictor response of sensitized human bronchus to antigen.