Drinking induced by parenteral injections of pilocarpine

Parenteral (IP) injections of pilocarpine, in doses from 3.75 - 30 mg/kg, reliably produced drinking in water-satiated rats. This effect was not diminished by pretreatment with either centrally active (scopolaime, atropine) or peripherally active (methyl scopolamine, methyl atropine) cholinergic blocking agents, suggesting that pilocarpine does not induce drinking via a cholingergic meachnism. Repated injections of low doses, but not high doses, of pilocarpine augments drinking over trials.