The relationship between cyclic AMP changes and histamine release from basophil-rich human leucocytes.

Histamine release and changes in cyclic AMP levels induced by a variety of stimuli have been measured in isolated human leucocytes from a patient with 40-70% basophilia. Adenosine and sodium fluoride induced early monophasic rises in cyclic AMP which peaked at 1 min, but they did not release histamine. 2',5'-Dideoxyadenosine (DDA) caused a transient fall in cyclic AMP levels. Anti-IgE, polylysine and calcium ionophore A23187 induced a slow release of histamine commencing 2-5 min after addition of secretagogue. With polylysine and A23187, release was still proceeding 45 min after challenge. In contrast, the chemotactic peptide formyl-methionyl-leucyl-phenylalanine (f-met-leu-phe) induced a rapid secretion of histamine which was complete within 2 min. Anti-IgE induced a rapid monophasic rise in cyclic AMP which reached a maximum at 45 sec and was inhibited by pretreatment with DDA. Cyclic AMP rises induced by polylysine and f-met-leu-phe were kinetically similar but smaller in magnitude. A23187 caused a later rise in cyclic AMP which peaked 3 min after challenge. A high concentration (50 microM) of compound 48/80 induced a slow cytotoxic release of histamine which was not accompanied by changes in cyclic AMP levels. The inconsistent quantitative and kinetic relationships of histamine release and cyclic AMP production suggest that changes in cyclic AMP levels may not play a key role in the biochemical events leading to mediator secretion from human basophil leucocytes.