Effect of Bay K 8644 on the synthesis and metabolism of dopamine and 5-hydroxytryptamine in various brain areas of the rat.
The effects of Bay K 8644 (1, 2 and 4 mg kg-1, i.p.) on the synthesis and metabolism of dopamine and 5-hydroxytryptamine (5-HT) in rat brain after m-hydroxybenzylhydrazine administration were studied. Bay K 8644 (2 and 4 mg kg-1, i.p.) caused an increase in the synthesis of both dopamine in the striatum and 5-HT in the midbrain and striatum, measured as the accumulation of 3,4-dihydroxyphenylalanine (dopa) and 5-hydroxytryptophan, respectively. Moreover, Bay K 8644 at the dose of 4 mg kg-1 increased the turnover of dopamine in the striatum and of 5-HT in midbrain and striatum. These neurochemical changes were antagonized by the calcium channel antagonist nimodipine (10 mg kg-1, i.p.). It is concluded that dihydropyridine receptors may mediate the brain region-specific changes in the dopaminergic and 5-HT-ergic neurotransmission which occur following activation of neuronal calcium channels.
Colado
M I
MI
Departamento de Farmacologia, Facultad de Medicina, Universidad Complutense, Madrid, Spain.
Ormazabal
M J
MJ
Alfaro
M J
MJ
Martin
M I
MI
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D006916:5-Hydroxytryptophan / Q000378:metabolism; D000818:Animals; D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D001923:Brain Chemistry / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D004298:Dopamine / Q000096:biosynthesis / Q000378:metabolism*; D006834:Hydrazines / Q000494:pharmacology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000096:biosynthesis / Q000378:metabolism*
D065105:Aromatic Amino Acid Decarboxylase Inhibitors; D006834:Hydrazines; D012701:Serotonin; D004295:Dihydroxyphenylalanine; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C004297:3-hydroxybenzylhydrazine; D006916:5-Hydroxytryptophan; D004298:Dopamine