[Cyclic adenosine 3-5 monophosphate (c-AMP) and allergy].

Cyclic adenosin-3-5-monophosphate (c-AMP) plays a central role in regulating immune responses. Increased intracellular c-AMP has an inhibitory effect on release of histamine and other mediators from basophile leukocytes or mast cells as well as lysosomal enzymes from polymorphs. It depresses cell-mediated immune reactions and antibody formation. The hormonal factors which increase intracellular c-AMP are either of neuroendocrine origin (e.g. epinephrin) or inflammatory products (e.g. prostaglandins and histamine). This seems to be an endogenous mechanism of regulation which is able to stop immune or allergic reactions. Patients suffering from atopic diseases (asthma and/or atopic dermatitis) show a decreased reactivity to betaadrenergic stimuli. The defect is demonstrable in vitro in peripheral leukocytes which show a significantly smaller increase in intracellular c-AMP after betaadrenergic stimulation than normal leukocytes.