Relationship between anti-acetylcholine and anti-Tremorine activity in anti-parkinsonian and related drugs.
The anti-acetylcholine potency of a number of anti-Parkinsonism drugs and related phenothiazine compounds was determined using the isolated guinea-pig ileum. The antagonism was assessed by the difference between the pA(2) and pA(10) values and by log concentration-response curves for acetylcholine in presence and absence of the antagonists. All compounds except chlorpromazine showed some evidence of competitive antagonism to acetylcholine. The anti-tremor potency of the compounds was assessed from suppression of Tremorine-induced tremors in mice. There was a relation between anti-acetylcholine and anti-Tremorine potency among the anti-Parkinsonism drugs, but not among the phenothiazine compounds. Some implications of the findings are discussed in relation to the mode of action of anti-Parkinsonism drugs.
D000109:Acetylcholine; D000818:Animals; D000978:Antiparkinson Agents; D014150:Antipsychotic Agents; D002746:Chlorpromazine; D018680:Cholinergic Antagonists; D006168:Guinea Pigs; D006571:Heterocyclic Compounds / Q000037:antagonists & inhibitors*; D007082:Ileum; D051379:Mice; D010300:Parkinson Disease; D010640:Phenothiazines / Q000494:pharmacology*; D014202:Tremor; D014203:Tremorine
D000978:Antiparkinson Agents; D014150:Antipsychotic Agents; D018680:Cholinergic Antagonists; D006571:Heterocyclic Compounds; D010640:Phenothiazines; C031637:phenothiazine; D000109:Acetylcholine; D002746:Chlorpromazine; D014203:Tremorine
ACETYLCHOLINE/antagonists; HETEROCYCLIC COMPOUNDS/antagonists; PARALYSIS AGITANS; PHENOTHIAZINES/pharmacology