title: Dose-response curves and time-course effects of selected anticholinergics on locomotor activity in rats.
abstract: BACKGROUND
  In order to facilitate direct comparisons of anticholinergic drug effects on activity, nine drugs were tested in one laboratory using a standardized procedure.
  
  
  OBJECTIVE
  The present study compared the effects of aprophen hydrochloride, atropine sulfate, azaprophen hydrochloride, benactyzine hydrochloride, biperiden hydrochloride, diazepam, procyclidine hydrochloride, scopolamine hydrobromide, and trihexyphenidyl hydrochloride on activity levels in rats.
  
  
  METHODS
  Both fine motor activity (reflecting smaller movements) and ambulatory activity (reflecting larger movements) were recorded for 23 h following drug administration in food-restricted rats. All drugs were administered during the light period of the photocycle.
  
  
  RESULTS
  Atropine, azaprophen, biperiden, scopolamine, and trihexyphenidyl increased both ambulations and fine motor activity significantly during the first hour post-injection, but the increased activity levels returned to vehicle control levels within 2-6 h post-injection. Benactyzine and procyclidine only increased fine motor activity significantly above vehicle control levels and activity levels returned to vehicle control levels within 2-3 h. Finally, aprophen and diazepam generally did not increase measures of activity significantly above vehicle controls at the dose ranges examined.
  
  
  CONCLUSIONS
  Based on potencies relative to scopolamine, the potency of the drugs could be ranked as follows: scopolamine > trihexyphenidyl > biperiden > azaprophen > procyclidine > benactyzine > atropine > aprophen. The comparison of drug effects on activity may be useful in selecting anticholinergic drug therapies with a minimal range of side effects. In addition, these data may reduce the number of anticholinergic drugs that need to be tested in comparison studies involving more complex behavioral tests.
authors.affiliation: Department of Neurobehavioral Assessment, Walter Reed Army Institute of Research, Washington, DC 20307-5100, USA. maurice.sipos@na.amedd.army.mil
authors.forename: M L
authors.initials: ML
authors.lastname: Sipos
authors.forename: V
authors.initials: V
authors.lastname: Burchnell
authors.forename: G
authors.initials: G
authors.lastname: Galbicka
mesh_terms: D000818:Animals; D018680:Cholinergic Antagonists / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D011597:Psychomotor Performance / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D018680:Cholinergic Antagonists