Histamine release in vitro: inhibition by catecholamines and methylxanthines

Methylxanthines and catecholamines both inhibit antigenically induced histamine release from human leukocytes. They act synergistically to inhibit the reaction, but must be present when antigen is added; preincubation is not effective. Since both increase cellular levels of cyclic 3 ', 5'-adenosine monophosphate it is postulated that this compound plays a role in the regulation of allergic histamine release.