Alterations of physostigmine-induced yawning by chronic lithium administration in rats.
The effect of chronic lithium pretreatment on physostigmine-induced yawning was investigated in male rats. Intraperitoneal administration of physostigmine to rats induced yawning in a biphasic manner. However the maximum response was obtained by 0.2 mg/kg of the drug. Intracerebroventricular administrations of a putative M1 and M2 muscarinic receptor antagonists, pirenzepine and methoctramine decreased physostigmine-induced yawning. Intraperitoneal administration of a non-selective muscarinic receptor antagonist, atropine, also decreased the physostigmine-induced yawning significantly. Chronic lithium pretreatment (30 days) reduced yawning induced by physostigmine. The inhibitory effect of pirenzepine, methoctramine and atropine on physostigmine-induced yawning increased in rats pretreated with chronic lithium. These findings indicate that yawning is induced by a central cholinergic mechanism and that chronic pretreatment of lithium may interact with the cholinergic-induced behaviour.
Sharifzadeh
M
M
Department of Toxicology & Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Iran.
Abdollahi
M
M
Dehpour
A R
AR
Kebriaeezadeh
A
A
Samini
M
M
Mohammad
M
M
D000818:Animals; D018692:Antimanic Agents / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D003959:Diamines / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D018021:Lithium Chloride / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D010276:Parasympatholytics / Q000494:pharmacology; D010830:Physostigmine / Q000008:administration & dosage*; D010890:Pirenzepine / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D015000:Yawning / Q000187:drug effects*
D018692:Antimanic Agents; D003959:Diamines; D018727:Muscarinic Antagonists; D010276:Parasympatholytics; D010890:Pirenzepine; D001285:Atropine; D010830:Physostigmine; D018021:Lithium Chloride; C054938:methoctramine