title: Deprenyl stimulates the efflux of monoamines from the rat hypothalamus in vitro.
abstract: The direct effects of L-deprenyl, a monoamine oxidase inhibitor, on the hypothalamus of male Sprague-Dawley rats was investigated by measuring the efflux of norepinephrine (NE), dopamine (DA), serotonin (5-HT), dihydroxyphenylacetic acid (DOPAC), and 5-hydroxyindoleacetic acid (5-HIAA) using a combination of high performance liquid chromatography with electrochemical detection and an in vitro incubation system. After measuring basal efflux by incubating the hypothalami with Krebs-Ringers Henseleit (KRH) alone during the first incubation period, hypothalami were incubated either with the medium, KRH alone (0 mM), or KRH containing 0.1, 1, and 10 mM L-deprenyl. During the third incubation period, hypothalami were again incubated with KRH alone to measure the residual effects if any. During the final incubation period, the hypothalami were stimulated with high K(+) KRH. Deprenyl produced a dose-dependent increase in the efflux of NE, DA, and 5-HT from the hypothalami. Neurotransmitter efflux returned to pretreatment levels when L-deprenyl was removed from the medium. In contrast to NE, DA, and 5-HT, the efflux of the metabolites DOPAC and 5-HIAA was inhibited in a dose-dependent fashion after incubation with L-deprenyl. Results from this study demonstrate that L-deprenyl is capable of stimulating the efflux of neurotransmitters in vitro by a direct action on the hypothalamus.
authors.affiliation: Neuroendocrine Research Laboratory, Department of Veterinary Pathology, College of Veterinary Medicine, Michigan State University, E. Lansing, MI 48824, USA. mohankumar@ahdlms.msu.edu
authors.forename: P S
authors.initials: PS
authors.lastname: MohanKumar
authors.forename: S M
authors.initials: SM
authors.lastname: MohanKumar
authors.forename: S K
authors.initials: SK
authors.lastname: Quadri
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D015306:Biogenic Monoamines / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007031:Hypothalamus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012642:Selegiline / Q000494:pharmacology*; D012701:Serotonin / Q000378:metabolism
chemical_list: D015306:Biogenic Monoamines; D008996:Monoamine Oxidase Inhibitors; D015102:3,4-Dihydroxyphenylacetic Acid; D012642:Selegiline; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine; D009638:Norepinephrine