Behavioural and anti-psychotic effects of Ca2+ channel blockers in rhesus monkey.
The potential utility of Ca2+ channel blockers in the treatment of various psychiatric disorders has been recently suggested. In the present study, the behavioural and anti-psychotic effects of Ca2+ channel blockers were investigated in unrestrained rhesus monkeys (Macaca mulatta) living together in a colony. The different behaviours categorised as social, solitary and abnormal were video recorded and analysed. Graded doses of verapamil (5-20 mg/kg, i.m.) and nimodipine (7.5-30 mg/kg, p.o.) produced a mild decrease in social and solitary behaviour without producing any cataleptic posture in the tested monkeys. In order to determine potential antipsychotic effects, Ca2+ channel blockers were studied in the model of amphetamine-induced psychosis. Amphetamine, at the dose of 2 mg/kg, i.m., induced suppression of approach, contact, grooming, and feeding, whilst vigilance (checking), stereotyped behaviour and oral hyperkinesia were increased in the monkeys. Pre-treatment with verapamil (10 and 20 mg/kg, i.m.) significantly suppressed amphetamine-induced hypervigilance, stereotypy, oral hyperkinesia and tachypnoea but was unable to reverse other amphetamine-induced behavioural effects. Nimodipine showed insignificant anti-psychotic effects at both 15 and 30 mg/kg doses. These results suggest that verapamil has a definite antipsychotic effect without any extrapyramidal side effects and thus may be of clinical significance in the treatment of psychosis.
Palit
G
G
Primate Behaviour Laboratory, Division of Pharmacology, Central Drug Research Institute, Post Box 173, 226001, Lucknow, India. root@cscdri.ren.nic.in
Kalsotra
A
A
Kumar
R
R
Nath
C
C
Dubey
M P
MP
D000661:Amphetamine; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D002121:Calcium Channel Blockers / Q000494:pharmacology* / Q000627:therapeutic use; D000697:Central Nervous System Stimulants; D004305:Dose-Response Relationship, Drug; D005260:Female; D008253:Macaca mulatta; D008297:Male; D009553:Nimodipine / Q000494:pharmacology* / Q000627:therapeutic use; D011618:Psychotic Disorders / Q000188:drug therapy; D013239:Stereotyped Behavior / Q000187:drug effects* / Q000502:physiology; D014700:Verapamil / Q000494:pharmacology* / Q000627:therapeutic use
D002121:Calcium Channel Blockers; D000697:Central Nervous System Stimulants; D009553:Nimodipine; D014700:Verapamil; D000661:Amphetamine