This study was undertaken to examine whether repeated alteration of dopamine turnover influences the function of dopamine uptake sites. In the first experiment, rats were repeatedly injected intraperitoneally with L-3,4-dihydroxyphenylalanine (L-DOPA), alpha-methyl-p-tyrosine or 1-[2-bis(4-fluorophenyl)methoxy]ethyl]-4-(3- phenylpropyl)piperazine (GBR 12909) once daily for 14 days. An increase in the number of [3H]mazindol binding sites in the striatum was seen with L-DOPA and GBR 12909. A decrease was seen with alpha-methyl-p-tyrosine. In the second experiment, the effect of a single treatment with the same drugs was investigated and no change in the number and affinity of [3H]mazindol binding sites was found. These results indicate that the number of dopamine uptake sites is modulated by persistent changes in dopamine turnover, and that repeated treatment with a selective dopamine uptake inhibitor, GBR 12909, increases their number.
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http://dx.doi.org/10.1016/0014-2999(93)90390-4 | DOI Listing |
Addict Biol
October 2010
Faculty of Health & Medical Sciences, Division of Biochemical Sciences, University of Surrey, UK.
Neuronal nAChR upregulation is the hallmark of chronic nicotine exposure. Neuroplasticity to abused drugs, however, depends on whether their administration is forced by the experimenter or is under the control of the experimental animal. Neuroadaptation to chronic nicotine self-administration was examined with a yoked-control paradigm, using nose-poking as the operating procedure.
View Article and Find Full Text PDFPsychopharmacology (Berl)
March 2010
Laboratori de Neurofarmacologia, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Calle Dr Aiguader 88, 08003 Barcelona, Spain.
Rationale: Repeated administration of 3,4-methylenedioxymethamphetamine (MDMA) produces mainly dopaminergic neurotoxicity in mice. However, the consequences of this exposure on the behavioural responses related to natural reinforcing stimuli are still largely unknown.
Objectives: We examined whether repeated treatment with neurotoxic and non-neurotoxic doses of MDMA could exert acute and long-lasting effects on the motivation of mice to obtain a highly palatable food and on the extinction and reinstatement of food-seeking behaviour.
Synapse
January 2008
Department of Pharmacology, College of Pharmacy, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
We have previously shown that 5-HT3 receptors are involved in the development and expression of methamphetamine (MAP)-induced locomotor sensitization in mice. In the present study, we further examined whether the dopaminergic system is involved in the attenuating effects of MDL 72222, a 5-HT3 receptor antagonist, on acute MAP-induced locomotor hyperactivity. For this, we examined alterations of dopamine (DA) in the form of D1 receptor, D2 receptor, and dopamine transporter (DAT) binding labeled with [3H]SCH23390 for D1, [3H]raclopride for D2, and [3H]mazindol for DAT binding in the mouse brains with acute MAP exposure or pretreatment of MDL 72222 with MAP.
View Article and Find Full Text PDFPsychopharmacology (Berl)
January 2006
Universitat Pompeu Fabra, Calle Dr. Aiguader, 80, 08003, Barcelona, Spain.
Rationale: MDMA is one of the most widely consumed recreational drugs in Europe. However, the mechanisms involved in the reinforcing properties of MDMA are still unclear. In this sense, the establishment of a reliable model of MDMA self-administration in mice could represent an important approach to study the neuronal substrates associated with MDMA reward by using genetically modified mice.
View Article and Find Full Text PDFCardiovasc Res
August 2005
Department of Cardiology, University of Heidelberg, INF 410, D-69120 Heidelberg, Germany.
Objective: Endothelin-1 (ET-1) potentiates norepinephrine (NE)-induced contractile responses. An impairment of cardiac NE re-uptake by the neuronal NE transporter (NET) contributes to an increased NE net release in failing hearts. We hypothesized that both phenomena are caused by ET-1-mediated inhibition of NET.
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