Drugs for Parkinson's disease reduce tremor induced by physostigmine.
The effects of anticholinergic and dopaminergic drugs used for Parkinson's disease were studied on the tremor induced by physostigmine (0.3-3.0 mg/kg) in rats. For the measurement of tremor a new electronic device was employed. Atropine (0.3-1.2 mg/kg) and biperiden (0.01-1.0 mg/kg) reduced the physostigmine-induced tremor in a dose-related manner and could abolish it. Biperiden was less potent than atropine. Methylatropine in a dose of 1.2 mg/kg slightly inhibited the tremor. Amantadine (0.3-3.0 mg/kg) reduced the tremor but only to a certain degree. Bromocriptine (0.1-10.0 mg/kg) reduced it in a manner that was not dose-related. Pimozide potentiated the tremor in the dose of 0.2 mg/kg but not in larger doses. At the onset of the tremor, a small decrease in rectal temperature occurred. The hypothermia lasted significantly longer than the tremor. Neither the anticholinergic nor the dopaminergic anti-Parkinson drugs altered the hypothermic effect of physostigmine. The results show that those anti-Parkinson drugs, which act by increasing the dopaminergic activity can counteract the tremor induced by physostigmine. However, these drugs are clearly less active than th anticholinergic anti-Parkinson drugs.
D000547:Amantadine / Q000494:pharmacology; D000818:Animals; D000978:Antiparkinson Agents / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D001712:Biperiden / Q000494:pharmacology; D001971:Bromocriptine / Q000494:pharmacology; D008297:Male; D010830:Physostigmine / Q000037:antagonists & inhibitors*; D010868:Pimozide / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014202:Tremor / Q000139:chemically induced / Q000188:drug therapy*
D000978:Antiparkinson Agents; D001712:Biperiden; D010868:Pimozide; D001971:Bromocriptine; D001285:Atropine; D010830:Physostigmine; D000547:Amantadine