Interactions of clozapine, thioridazine, and mezilamine with oxotremorine on schedule-controlled responding.
The effects of clozapine (0.64-10 mg/kg IM), thioridazine (5-80 mg/kg IM), and mezilamine (0.1-10 mg/kg IM) were determined alone and the presence of 0.05 mg/kg oxotremorine on multiple fixed-ratio, fixed-interval responding in pigeons. All three drugs alone produced a dose-related decrease in responding. Thioridazine and mezilamine produced greater decreases in fixed-interval responding than fixed-ratio responding. Oxotremorine alone decreased responding to 10% of control. Clozapine and thioridazine produced a dose-related antagonism of the behavior-suppressing effects of oxotremorine with 5 mg/kg clozapine completely reversing the behavior-suppressing effects of oxotremorine. In contrast, mezilamine produced no antagonism of the behavior-suppressing effects of oxotremorine. It was concluded that the effects of clozapine on schedule-controlled responding in the pigeon are due to its anticholinergic effects, rather than to its antipsychotic-like effects. Thioridazine also has prominent anticholinergic effects, whereas mezilamine does not have anticholinergic effects.
D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology*; D003024:Clozapine / Q000494:pharmacology*; D010856:Columbidae; D003213:Conditioning, Psychological / Q000187:drug effects*; D003984:Dibenzazepines / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D010095:Oxotremorine / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D013881:Thioridazine / Q000494:pharmacology*; D013997:Time Factors
D014150:Antipsychotic Agents; D003984:Dibenzazepines; D011743:Pyrimidines; D010095:Oxotremorine; D003024:Clozapine; D013881:Thioridazine; C014287:mezilamine