Inhibition of slow-reacting substance release by calmodulin blocker.
It was examined whether a calmodulin blocker could inhibit release of slow-reacting substance from human leukocytes. W-7, a specific calmodulin blocker, completely inhibited slow-reacting substance release induced by calcium ionophore or mite allergen at 5 X 10(-5) M, while W-12, which had a lower affinity to calmodulin, failed to inhibit the release even at 10(-4) M. It was suggested that calmodulin was involved in mechanisms of slow-reacting substance release. Release of PGE2 and PGF2 alpha by calcium ionophore was partially inhibited by 5 X 10(-5) M of W-7. The inhibitory effects of W-7 on slow-reacting substance release could be considered responsible for the suppression of phospholipase A2.
D012898:Autacoids / Q000378:metabolism*; D000001:Calcimycin / Q000494:pharmacology; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D004110:Diltiazem / Q000494:pharmacology; D006801:Humans; D007962:Leukocytes / Q000187:drug effects; D008925:Mites; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology; D014020:Tissue Extracts / Q000494:pharmacology
D012898:Autacoids; D002147:Calmodulin; D013449:Sulfonamides; D014020:Tissue Extracts; C040184:W 12; D000001:Calcimycin; C017967:W 7; D004110:Diltiazem