Influence of different histamine receptor agonists and antagonists on apomorphine-induced licking behavior in rat.
The effects of different histamine receptor agonists and antagonists on apomorphine-induced licking behavior in rats were investigated. Subcutaneous (s.c.) injection of various doses of apomorphine (0. 125-1.25 mg/kg) induced licking. The licking response was counted by direct observation and recorded for a 75-min period. Intracerebroventricular (i.c.v.) or intraperitoneal (i.p.) injection of the histamine H(1) or H(2) receptor agonist, HTMT (6-[2-(4-imidazolyl)ethylamino]-N-(4-trifluoromethylphenyl) heptanecarboxamide) (50 and 100 microg per rat), or dimaprit (10 and 15 mg/kg, i.p.), respectively, potentiated apomorphine-induced licking, while the histamine H(3) receptor agonist, imetit (5 and 10 mg/kg, i.p.), reduced the licking response induced by apomorphine. Pretreatment with various histamine receptor antagonists, dexchlorpheniramine (30 and 40 mg/kg, i.p.), diphenhydramine (20, 30 and 40 mg/kg, i.p.), famotidine (30 and 40 mg/kg, s.c.) and ranitidine (20, 30 and 40 mg/kg), reduced apomorphine-induced licking, while thioperamide (5 and 10 mg/kg, i.p.) potentiated the apomorphine effect. The effects of HTMT and dimaprit were blocked by dexchlorpheniramine (20 mg/kg, i.p.) and famotidine (20 mg/kg, s.c.), respectively. The inhibitory effect elicited by imetit on apomorphine-induced licking behavior was also abolished in animals treated with thioperamide (2.5 mg/kg, i.p.). The results suggest that histaminergic mechanisms may be involved in the modulation of apomorphine-induced licking behavior.
Farzin
D
D
Department of Pharmacology, Sari School of Medicine, Mazandaran University of Medical Sciences, 48168, Sari, Iran. davood.farzin@planetaccess.com
Attarzadeh
M
M
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D002744:Chlorpheniramine / Q000494:pharmacology; D017259:Dimaprit / Q000494:pharmacology; D004155:Diphenhydramine / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D004347:Drug Interactions; D015738:Famotidine / Q000494:pharmacology; D006632:Histamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D017442:Histamine Agonists / Q000494:pharmacology*; D006633:Histamine Antagonists / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology; D008297:Male; D010880:Piperidines / Q000494:pharmacology; D011899:Ranitidine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013239:Stereotyped Behavior / Q000187:drug effects*; D013890:Thiourea / Q000031:analogs & derivatives* / Q000494:pharmacology; D014052:Toluidines / Q000494:pharmacology
D018491:Dopamine Agonists; D017442:Histamine Agonists; D006633:Histamine Antagonists; D007093:Imidazoles; D010880:Piperidines; D014052:Toluidines; C081972:6-((2-(4-imidazolyl)ethyl)amino)heptanoic acid 4-toluidide; C018904:dexchlorpheniramine; D002744:Chlorpheniramine; D015738:Famotidine; C077430:imetit; D006632:Histamine; D011899:Ranitidine; D004155:Diphenhydramine; D013890:Thiourea; C052075:thioperamide; D001058:Apomorphine; D017259:Dimaprit