title: Effects of harmane and other β-carbolines on apomorphine-induced licking behavior in rat.
abstract: Harmane, harmine and norharmane are β-carboline compounds which have been referred to as inverse agonists of benzodiazepine receptors. The effect of these compounds on apomorphine-induced licking behavior was studied in rats. Subcutaneous (s.c.) injection of apomorphine (0.5 mg/kg) induced licking. The licking behavior was counted with a hand counter and recorded for a period of 75 min by direct observation. Intraperitoneal (i.p.) injections of harmane (1.25-5 mg/kg), harmine (2.5-10 mg/kg) and norharmane (1.25-5 mg/kg) significantly reduced the licking behavior. In rats pretreated with reserpine (5 mg/kg, i.p., 18 h before the test), the effects of harmane (4 mg/kg, i.p.), harmine (7.8 mg/kg, i.p.) and norharmane (2.5 mg/kg, i.p.) were unchanged. When flumazenil (2 mg/kg, i.p.) was administered 20 min before apomorphine, it was able to antagonize the effects of harmane, harmine and norharmane. It was concluded that the β-carbolines harmane, harmine and norharmane reduce the licking behavior via an inverse agonistic mechanism located in the benzodiazepine receptors.
authors.affiliation: Department of Pharmacology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. davoodfarzin@yahoo.com
authors.forename: Davood
authors.initials: D
authors.lastname: Farzin
authors.forename: Abbas
authors.initials: A
authors.lastname: Haghparast
authors.forename: Shirine
authors.initials: S
authors.lastname: Motaman
authors.forename: Faegheh
authors.initials: F
authors.lastname: Baryar
authors.forename: Nazanin
authors.initials: N
authors.lastname: Mansouri
mesh_terms: D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D002243:Carbolines / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology; D018491:Dopamine Agonists / Q000494:pharmacology; D004347:Drug Interactions; D005442:Flumazenil / Q000494:pharmacology; D006247:Harmine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000187:drug effects / Q000502:physiology; D012110:Reserpine / Q000494:pharmacology; D013239:Stereotyped Behavior / Q000187:drug effects* / Q000502:physiology
chemical_list: D002243:Carbolines; D018491:Dopamine Agonists; D011963:Receptors, GABA-A; D005442:Flumazenil; D006247:Harmine; C005010:harman; D012110:Reserpine; C010262:norharman; D001058:Apomorphine