caa a22 4500 469078723 CHVBK 20180323132943.0 cr unu---uuuuu 170328e19920801xx s 000 0 eng 10.1007/BF00165298 doi (NATIONALLICENCE)springer-10.1007/BF00165298 Extraneuronal uptake of noradrenaline in rabbit dental pulp: evidence of identity with uptake [Elektronische Daten] [V. Marino, I. de la Laude, D. Parker, J. Dally, S. Wing] Summary: The extraneuronal removal and disposition of noradrenaline in rabbit dental pulp was examined in view of earlier evidence that the tissue possessed an extra-neuronal uptake process resembling neuronal uptake1. Pulp, which had been depleted of sympathetic nerves by homolateral superior cervical ganglionectomy, was incubated in vitro with 3H-noradrenaline in low concentrations (0.025 or 0.18 μmol/l). When the metabolising enzymes (monoamine oxidase, catechol-O-methyl transferase) were active, 3H retention by the denervated pulp, as indicated by the 3H content after the tissue had been washed for 30 min following incubation with 3H-noradrenaline, was less than 30% of that of the innervated pulp. When the enzymes were inhibited, retention rose to approximately 30% of that of the innervated pulp. Analysis of the time course of the 3H efflux indicated that the 3H-noradrenaline in the denervated pulp had accumulated in a single compartment characterised by a t1/2 for efflux of several hours. Accumulation did not occur under Na+-free conditions, and was inhibited by desipramine (IC50 < 0.03 μmol/l) and by substrates of neuronal uptake1. Mean IC50, values of the latter were very similar to those for inhibition of neuronal uptake1 and comprised (in μmol/l): (+)amphetamine (0.29), dopamine (0.31), tyramine (0.39), (−)noradrenaline (0.70), (−)adrenaline (1.50), 5-hydroxytryptamine (20) and bretylium (35). Uptake2 inhibitors were less active (O-methyl isoprenaline, IC50 = 60 μmol/l) than uptake1 inhibitors, or were without inhibitory effects at the concentrations tested (hydrocortisone, 210 μmol/l; 2-methoxy oestrone, 10 μmol/l). The effects of Na+ omission, of (+)amphetamine, and of O-methylisoprenaline on 3H-normetanephrine formation (measured in the absence of catechol-O-methyl transferase inhibition) matched their effects on 3H-noradrenaline accumulation. The results provide strong support for the presence in rabbit dental pulp of extraneuronal uptake1 which is linked with catechol-O-methyl transferase in the removal of noradrenaline. Springer-Verlag, 1992 Dental pulp nationallicence Noradrenaline nationallicence Extraneuronal uptake1 nationallicence O-methylation nationallicence Marino V. Department of Dentistry, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut de la Laude I. Department of Clinical and Experimental Pharmacology, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut Parker D. Department of Dentistry, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut Dally J. Department of Dentistry, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut Wing S. Department of Dentistry, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/2(1992-08-01), 166-172 0028-1298 346:2<166 1992 346 210 https://doi.org/10.1007/BF00165298 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00165298 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Marino V. Department of Dentistry, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- de la Laude I. Department of Clinical and Experimental Pharmacology, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- Parker D. Department of Dentistry, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- Dally J. Department of Dentistry, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- Wing S. Department of Dentistry, The University of Adelaide, G.P.O. Box 498, 5000, Adelaide, South Australia, Australia aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/2(1992-08-01), 166-172 0028-1298 346:2<166 1992 346 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer