Acute effects of cholecystokinin tetrapeptide on brain stem auditory evoked potentials in healthy volunteers.
This study investigated the effects of continuous slow intravenous infusion of cholecystokinin tetrapeptide (CCK-4) on brain stem auditory evoked potentials (BSAEP) in healthy subjects. Twenty-four subjects, 15 females and 9 males, were assigned to infusion with either placebo or CCK-4 in a randomized, double-blind, parallel group design. BSAEPs, mood, physical symptoms, and vital signs were assessed once before infusion and at 10 min and 40 min after the onset of infusion. In the 16 subjects (N = 8, CCK-4; N = 8, placebo) CCK-4, compared to placebo, delayed peak I latency during early infusion, slowed the latencies of peaks III and V, and decreased the amplitude of peak III throughout the infusion. No significant treatment differences were observed with respect to symptoms, mood, or cardiovascular measures. These preliminary findings suggest that CCK-4 may interfere with information processing in the brain stem auditory pathways and that prolonged intravenous CCK-4 administration may be a useful challenge paradigm for investigating CCK's modulatory role on brain stem mechanisms mediating anxiety and panic in humans.