Inhibitory Effect of N-(3,4-Dimethoxycinnamoyl)anthranilic Ac d on Release of SRS from Alveolar Macrophages in Vitro

Abstract

The effects of N-(3,4-dimethoxycinnamoyl)anthranilic acid (N-5') on the release of the slow-reacting substance (SRS) by zymosan- or Ca ionophore-stimulated rat and human alveolar macrophages (AM) were examined in vitro. Disodium cromoglycate (DSCG) was used as a control. N-5' at concentrations of 10−4—10−3 M significantly inhibited the release of SRS from both rat and human AM stimulated by zymosan. N-5' had almost the same inhibitory effect when added to the AM culture system at any time from 180 min before to 30 min after the addition of zymosan. N-5' (10−4-10−3 M) also significantly inhibited the release of SRS by Ca ionophore-stimulated rat AM. N-5' (10−6—10−3 M) had no significant effect on phagocytosis of yeast particles by rat AM DSCG (10“6—10−3 M) did not inhibit the release of SRS from the zymosan-stimulated rat AM. N-5' was concluded to have a relatively specific inhibitory effect on the non-immunological release of SRS from stimulated AM. It is postulated that N-5' inhibits the process of release of SRS from AM by acting after the initial stage.