Modification of cholinergic tremor by apomorphine and L-dopa in rats.
Pretreatment with apomorphine, increased and prolonged the arecoline-induced tremor in rats. When given before pilocarpine, it produced different effects dependent on the dose: low doses (0.05 and 1.0 mg/kg) antagonized, but higher doses (5.0 and 10.0 mg/kg) enhanced the pilocarpine tremor. The extent and duration of arecoline tremor after pretreatment L-DOPA increased significantly, but this was not observed in the pilocarpine-induced tremor. These results suggest that the relations between striatal dopaminergic and cholinergic systems may be complex and the model based on a simple antagonism between these systems may be oversimplified.
D000818:Animals; D001058:Apomorphine / Q000008:administration & dosage*; D001115:Arecoline / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D007980:Levodopa / Q000008:administration & dosage*; D008297:Male; D010862:Pilocarpine / Q000009:adverse effects; D011292:Premedication; D051381:Rats; D014202:Tremor / Q000139:chemically induced / Q000188:drug therapy*
D010862:Pilocarpine; D007980:Levodopa; D001115:Arecoline; D001058:Apomorphine