INHIBITION OF COMPOUND 48/80-MEDIATED HISTAMINE RELEASE FROM ISOLATED RAT MAST CELLS BY OOSPONOL-RELATED COMPOUNDS (4-ACYL-ISOCOUMARINS)

摘要

References(13) Cited-By(3) Oosponol (4-hydroxymethylketone-8-hydroxyisocoumarin) is a metabolic product isolated from Oospora astringens which originated from house dust in a room of an asthmatic patient. The compound and the structurally related isocoumarins were studied to determine the inhibition of histamine release induced by compound 48/80 from isolated rat peritoneal mast cells. The released histamine was assayed by fluorometry. The compounds tested were not observed to release histamine. Some of 4-acyl-isocoumarins inhibited the histamine release at doses less than 10 μM, whereas the 3-acyl and the 4-alkyl-compounds were not effective at doses over 100 μM. The pretreatment of mast cell with the compound for 15 min before the application of compound 48/80 was more effective than the simultaneous administration. The mode of inhibitory action of KIT-302, 4-(4'-carboxy-benzoyl)-isocoumarin, was non-competitive antagonism to compound 48/80 on the mast cells.