caa a22 4500 469077867 CHVBK 20180323132940.0 cr unu---uuuuu 170328e19920701xx s 000 0 eng 10.1007/BF00167571 doi (NATIONALLICENCE)springer-10.1007/BF00167571 Effects of taurine, homotaurine and GABA on hypothalamic and striatal dopamine metabolism [Elektronische Daten] [Elina Panula-Lehto, Minna Mäkinen, Liisa Ahtee] Summary: To elucidate the effects of taurine on hypothalamic and striatal dopaminergic neurotransmission we compared its effects to those of γ-aminobutyric acid (GABA) and homotaurine (a GABAA-receptor agonist) on hypothalamic and striatal concentrations of dopamine (DA) and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and, in the case of striatum, 3-methoxytyramine (3-MT) in rats. In addition, hypothalamic and striatal 5-hydroxytryptamine (5-HT) und 5-hydroxyindoleacetic acid, hypothalamic noradrenaline (NA) and 3-methoxy-4-hydroxyphenylglycol sulfate, and pituitary DA concentrations were also measured. The amino acids were injected into the lateral brain ventricles of conscious male rats in doses of 10 and 36 μmol/rat, and rat were sacrificed 15 and 60 min later, respectively. Homotaurine (by 11010) but not the other two amino acids elevated striatal DA, whereas hypothalamic DA was increased by both taurine (36%) and homotaurine (31%). All three amino acids at 36 μmol elevated striatal DOPAC, homotaurine (51%) more than taurine (31%) or GABA (30%), and hypothalamic DOPAC, both taurine (102%) and homotaurine (82%) clearly more than GABA (34%). Neither striatal nor hypothalamic HVA was altered by any of the amino acids. At 10 μmol the amino acids decreased striatal 3-MT by about 40%. At 36 μmol taurine and homotaurine reduced 3-MT by about 70%, whereas increasing the dose of GABA did not further reduce 3-MT. Both taurine and homotaurine at 36 μmol decreased hypothalamic NA content. Neither hypothalamic nor striatal 5-HT metabolism was altered. In the neurointermediate lobe of the pituitary gland taurine at 10 μmol but not at 36 μmol slightly (20%) increased DA. These results show that taurine and homotaurine clearly alter the hypothalamic DA metabolism, and give further support to the suggestion that taurine and homotaurine similarly to GABA reduce the release of DA in the striatum. Homotaurine seems to alter the striatal DA metabolism more effectively than taurine or GABA. On the other hand, hypothalamic DA seems to be equally sensitive to taurine and homotaurine, and is clearly less sensitive to GABA. The pronounced elevation of hypothalamic DA and DOPAC after taurine and homotaurine could be related to changes in hypothalamic NA. Springer-Verlag, 1992 Taurine nationallicence Homotaurine nationallicence GABA nationallicence Striatal dopamine nationallicence Hypothalamic dopamine nationallicence Hypothalamic noradrenaline nationallicence Panula-Lehto Elina Division of Pharmacology and Toxicology, Department of Pharmacy, University of Helsinki, Kirkkokatu 20, SF-00170, Helsinki, Finland aut Mäkinen Minna Division of Pharmacology and Toxicology, Department of Pharmacy, University of Helsinki, Kirkkokatu 20, SF-00170, Helsinki, Finland aut Ahtee Liisa Division of Pharmacology and Toxicology, Department of Pharmacy, University of Helsinki, Kirkkokatu 20, SF-00170, Helsinki, Finland aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/1(1992-07-01), 57-62 0028-1298 346:1<57 1992 346 210 https://doi.org/10.1007/BF00167571 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00167571 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Panula-Lehto Elina Division of Pharmacology and Toxicology, Department of Pharmacy, University of Helsinki, Kirkkokatu 20, SF-00170, Helsinki, Finland aut NATIONALLICENCE 700 1- Mäkinen Minna Division of Pharmacology and Toxicology, Department of Pharmacy, University of Helsinki, Kirkkokatu 20, SF-00170, Helsinki, Finland aut NATIONALLICENCE 700 1- Ahtee Liisa Division of Pharmacology and Toxicology, Department of Pharmacy, University of Helsinki, Kirkkokatu 20, SF-00170, Helsinki, Finland aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/1(1992-07-01), 57-62 0028-1298 346:1<57 1992 346 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer