caa a22 4500 469079150 CHVBK 20180323132944.0 cr unu---uuuuu 170328e19920601xx s 000 0 eng 10.1007/BF00164581 doi (NATIONALLICENCE)springer-10.1007/BF00164581 Dopamine releasing effect of phenylbiguanide in rat striatal slices [Elektronische Daten] [Myron Benuck, Maarten Reith] Summary: The present study explored the mechanisms underlying the dopamine releasing effect of phenylbiguanide, a compound commonly used as a 5-HT3 receptor agonist. Phenylbiguanide, and also serotonin and 2-methyl-serotonin, enhanced the outflow of radioactivity from superfused rat striatal slices preloaded with [3H]dopamine. The presence of the dopamine uptake blocker nomifensin prevented the increase in outflow. The effect of phenylbiguanide was not antagonized by 5-HT3 receptor antagonists, did not require the presence of Ca2+ in the superfusion buffer, and also occurred in reserpinized preparations with depleted dopamine stores. Phenylbiguanide caused a greater shift in the distribution of superfusate radioactivity from DOPAC to dopamine than did nomifensin. All these results are in agreement with an exchange mechanism by which phenylbiguanide promotes the efflux of dopamine by operation of the uptake carrier in the reversed direction. In consonance, phenylbiguanide, and also serotonin and 2-methyl-serotonin, inhibited the binding of [3H]CFT to dopamine uptake sites, although the rank order for promoting outflow, serotonin > phenylbiguanide > 2-methyl-serotonin, differed from that for inhibiting [3H]CFT binding to dopamine uptake sites, 2-methylserotonin ∼ serotonin > phenylbiguanide. The present results raised the possibility that phenylbiguanide has an additional activity in releasing vesicular dopamine into the cytoplasmic pool. Springer-Verlag, 1992 Phenylbiguanide nationallicence 5-HT3 receptor agonists nationallicence 5-HT3 receptor antagonists nationallicence Dopamine transporter nationallicence Dopamine release nationallicence Rat striatum nationallicence Benuck Myron Division of Neurochemistry, N.S. Kline Institute for Psychiatric Research, Building 39, Oak and Plaza Sts., 10962, Orangeburg, NY aut Reith Maarten Division of Neurochemistry, N.S. Kline Institute for Psychiatric Research, Building 39, Oak and Plaza Sts., 10962, Orangeburg, NY aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/6(1992-06-01), 666-672 0028-1298 345:6<666 1992 345 210 https://doi.org/10.1007/BF00164581 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00164581 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Benuck Myron Division of Neurochemistry, N.S. Kline Institute for Psychiatric Research, Building 39, Oak and Plaza Sts., 10962, Orangeburg, NY aut NATIONALLICENCE 700 1- Reith Maarten Division of Neurochemistry, N.S. Kline Institute for Psychiatric Research, Building 39, Oak and Plaza Sts., 10962, Orangeburg, NY aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/6(1992-06-01), 666-672 0028-1298 345:6<666 1992 345 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer