Invited Symposium: Molecular and Cellular Analysis of Dopamine and Serotonin Transporters
Demirgoren, S. (Ege University Center for Brain Research, Izmir, Turkey)
Taskiran, D. (Ege University Center for Brain Research, Izmir, Turkey)
Kuhar, M.J. (Emory University, Yerkes Regional Primate Center, Atlanta, USA)
Pogun, S. (Ege University Center for Brain Research, Izmir, Turkey)
Neurotransmitter transporters terminate the action of released neurotransmitter by reuptake. NO has been shown to inhibit uptake of dopamine (DA) and glutamate (glu) in a dose-, time- and temperature dependent fashion in synaptosomes. Inhibition of transporters for some neurotransmitters in brain by NO may be a new type of transynaptic retrograde regulation mechanism for uptake regulation. The present study was undertaken to study the effects of in-vivo NOS inhibition on ex-vivo dopamine and glutamate uptake. Male Sprague Dawley rats were injected with N Nitro-L-arginine (50 mg/kg) or saline and decapitated at various times post-injection (5, 10, 15, 30, 60, 120 min); 3H-DA and 3H-Glu uptake and stable metabolites of NO (NO2+NO3) were determined in synaptosomes prepared from the striatum and hippocampus. Our results show a significant facilitation of both DA and Glu uptake at 15 min post-injection, when the total NO2+NO3 levels also start to fall. However, while lower NO2+NO3 levels persist up to 120 minutes, the facilitation of transport does not accompany this decline, implying a possible compensatory mechanism. Our results suggest that NOS inhibition and the subsequent lowering of brain NO levels result in a transient facilitation of DA and glu uptake in rat striatum and hippocampus, respectively.
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|Koylu, E.O.; Demirgoren, S.; Taskiran, D.; Kuhar, M.J.; Pogun, S.; (1998). In-vivo Nitric Oxide Synthase (NOS) Inhibition Facilitates Dopamine And Glutamate Transport.. Presented at INABIS '98 - 5th Internet World Congress on Biomedical Sciences at McMaster University, Canada, Dec 7-16th. Invited Symposium. Available at URL http://www.mcmaster.ca/inabis98/simantov/koylu0147/index.html|
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