BACKGROUNDThe authors determined whether effective beta-adrenergic blockade could attenuate the panicogenic effects of cholecystokinin-tetrapeptide (CCK-4) in healthy volunteers.METHODSSubjects were randomly assigned to either a propranolol (n = 14) or placebo (n = 16) infusion. Ten minutes after completion of the infusion subjects received a bolus injection of CCK-4 (50 micrograms).RESULTSAcute pretreatment with propranolol was more effective than placebo in decreasing behavioral and cardiovascular sensitivity.CONCLUSIONSThese preliminary results suggest that the panicogenic effects of CCK-4 are mediated, in part, through the beta-adrenergic system.