Comparative in vitro effects of arachidonic acid metabolites on tracheal spirals and parenchymal strips

We compared the pharmacologic effects of a number of oxidative products of arachidonic acid metabolism, including prostaglandin (PG) F2 alpha, PGD2, PGI2, PGE2 6-keto-PGF1 alpha, and the 9 alpha, 11 alpha and 11 alpha, 9 alpha cyclic ether endoperoxide analogues, with that of histamine on guinea pig tracheal spirals and lung parenchymal strips. These agents demonstrated different profiles of activity on the tracheal (central) and parenchymal (peripheral) airway tissues. None of the metabolites studied exceeded the ability of histamine to constrict the tracheal spirals, whereas the cyclic ether endoperoxide analogues and PGD2 were as good as, or better, constrictors of the parenchymal strips than histamine. This suggests that these mediators, which are formed during hypersensitivity reactions, may play an important role in the peripheral airway constriction that is a part of this syndrome.