Inhibition of immunological and non-immunological histamine release from human basophils by adenosine analogues that act at P-sites

Abstract

2',5'-Dideoxyadenoside (DDA) inhibited both anti-IgE and ionophore A23187 induced histamine secretion from human basophils. Whereas DDA inhibited IgE-dependent histamine secretion when added at all times prior to challenge, release induced by A23187 was inhibited only with simultaneous addition of DDA and secretagogue. Dipyridamole, but not theophylline, abrogated DDA mediated inhibition of histamine release suggesting an intracellular mechanism of action of DDA. The observations that 2'-deoxyadenosine and 9-β- d-arabinofuranosyladenine also inhibited release suggest that the inhibitory effect is produced by an interaction with internal P-sites. Furthermore, the obser vations that its inhibitory effect was enhanced by manganese and reversed by islet activating protein from Bordetella pertussis suggest that DDA inhibits basophil histamine release by interacting with a guanine nucleotide binding protein which may be linked to either adenylate cyclase or other second messenger system(s).