Abstract
The pharmacological effects of N-[2-(4-(bezhydryloxy)piperidino)ethyl] -3-hydroxy-5-(3pyridylmethoxy)-2-naphthamide (F-1322), a novel anti-asthmatic agent, was investigated in vitro. The results obtained were as follows: 1) In the isolated trachea of guinea pigs, F-1322 showed a markedly potent antagonistic action against the contraction induced by histamine, while it had little or no effect on 5-hydroxytryptamine-, acetylcholine-, leukotriene D4- or U-46619-induced contractions. 2) In rabbit platelets, F-1322 did not affect the platelet aggregation induced by platelet activating factor. 3) F-1322 significantly inhibited the thromboxane (TX) A2 synthetase (IC50 value: 1.7 × 10-8 M) and 5-lipoxygenase (IC50 value: 9 × 10-7 M) activities. 4) F-1322 had no effect on phospholipase A2, cyclooxygenase, Ca2+/calmodulin-dependent phosphodiesterase and phosphodiesterase activities. These in vitro studies suggest that the anti-asthmatic action of F-1322 is associated with histamine antagonism and an inhibitory action on TXA2 synthetase and 5-lipoxygenase activities.
