Changes in pancreatic exocrine secretion after repeated haloperidol administration.

The effect of repeated administration of haloperidol on the pancreatic secretion was studied in urethane-anesthetized Swiss mice. Haloperidol (2 mg/kg) injected daily i.p. for 7 days, increase the volume and protein content of the basal pancreatic juice significantly. This secretory activity was partially blocked by i.p. injection of atropine (5 mg/kg), both in control and treated animals. The volume of the secretory response to bethanechol, a cholinergic agonist, was decreased by haloperidol without any change in amylase release. From these findings it is concluded that repeated haloperidol treatment produces an increase of basal pancreatic secretion, which is probably the result of changes in the sensitivity of dopamine receptors of the gland.