Epinephrine potentiates the analgesic and antidepressant effects of polyvinylpyrrolidone and cholecystokinin due to stimulation of afferents in the gastric mucosa.

Treatment with epinephrine, polyvinylpyrrolidone, and cholecystokinin in the minimum effective doses produced maximum analgesic and antidepressant effects and caused bradycardia in rats. Administration of epinephrine in combination with polyvinylpyrrolidone or cholecystokinin in threshold doses (1/10-1/25 of the minimum effective dose) produced maximum analgesic and antidepressant effects, but did not cause bradycardia. The potentiating effect of epinephrine is related to stimulation of afferents in the gastric mucosa.