title: Effects of nimodipine on biogenic amines in discrete brain areas.
abstract: Discrete brain sections were obtained from rats after once or repeatedly given intraperitoneal nimodipine at doses ranging from 2.5 to 40 mg/kg. The single or the last treatment was carried out at 2-8 h before killing. The biogenic amine and metabolite content of the tissue samples were determined by high-performance liquid chromatography with electrochemical detection. The nimodipine-induced effects, chiefly regarding the brainstem, the thalamus-midbrain and the striatum, consisted of both an increase in 5-hydroxyindoleacetic acid (5-HIAA) levels and a decrease in dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels. Since the 5-HIAA/5-hydroxytryptamine (5-HT) ratio was increased, whereas the DOPAC/dopamine (DA) and HVA/DA ratios were decreased, it was argued that nimodipine activated the serotonergic and inhibited the dopaminergic systems. The first effect was enhanced by fasting and, likewise, by drug administration repeated for 5 days, while the second was not affected by fasting, but disappeared after 5 days' treatment. The data obtained appeared to substantiate the usefulness of nimodipine to treat some disorders of the central nervous system.
authors.affiliation: Department of Pharmacology, University of Bologna, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Gaggi
authors.forename: A M
authors.initials: AM
authors.lastname: Gianni
authors.forename: L
authors.initials: L
authors.lastname: Chirivi
authors.forename: P
authors.initials: P
authors.lastname: Roncada
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D015306:Biogenic Monoamines / Q000378:metabolism*; D001933:Brain Stem / Q000187:drug effects* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006719:Homovanillic Acid / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007274:Injections, Intraperitoneal; D008297:Male; D009553:Nimodipine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism; D013788:Thalamus / Q000187:drug effects* / Q000378:metabolism
chemical_list: D015306:Biogenic Monoamines; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D009553:Nimodipine; D006719:Homovanillic Acid