ENHANCING IN-VIVO EFFECT OF PROPRANOLOL ON HUMAN LYMPHOCYTE FUNCTION IS NOT DUE TO STEREOSPECIFIC BETA-ADRENERGIC-BLOCKADE

Immunoenhancing in vivo effects of beta-adrenergic blockers have been previously ascribed to a reduced beta-receptor-mediated immunosuppress ion. In the present study using a whole blood stimulation assay, the e ffects of a five-day treatment with the purified (R)- or (S)-isomer of propranolol (3 x 40 mg/day) on the polyclonal in vitro responsiveness of peripheral blood lymphocytes (PBL) of normothyroid and hyperthyroi d persons were assessed. It is shown that both isomers likewise exhibi t a significant enhancing effect on the proliferative response of PBL to T and B cell mitogens, which strongly argues for nonspecific effect s of propranolol to be responsible rather than a specific beta-adrener gic receptor blockade.