Do mast cell degranulators release prostaglandins from frog atria?
Isolated atria of frogs responded to compound 48/80 and d-tubocurarine with a delayed stimulation that showed tachyphylaxis and cross-tachyphylaxis indicating a common indirect mechanism. The blockers of H2-histamine, serotonin and beta-adrenergic receptors did not significantly antagonise these responses. However, in experiments with ex vivo and in vitro indomethacin-treated atria, the stimulant effects of mast cell degranulators were not observed, indicating a possible involvement of the prostaglandins.