Abstract
The ionophore A23187 stimulated the release of prosta-glandins and SRS-A (now identified as leukotriene D4) from guinea-pig bronchoalveolar macrophages. Upon specific antigen challenge of the cells obtained from ovalbumin-sensi-tized animals or of normal cells preincubated with the serum of sensitized animals, prostaglandins, SRS-A or histamine were undetectable. Furthermore, treatment of “sensitized” cells with the ionophore resulted in a reduced liberation of prostaglandins in comparison to control cells. It is suggested that sensitization produce in bronchoalveolar macrophages some functional alterations of arachidonic acid oxy-genation products.