Biochemical characterization of [3H]norepinephrine uptake in dissociated brain cell cultures from chick embryos.
The uptake of [3H]norepinephrine ([3H]NE) was studied in dissociated brain cell cultures prepared from 8-day-old chick embryos using the whole brain (minus optic lobes). Uptake [3H]NE, 5 x 10(-9) m, 10 min incubation, in freshly dissociated noncultured embryonic chick brain cells, was detected in 6-day-old embryos; it was temperature and drug (cocaine, metanephrine) sensitive and increased with brain development. In cultured cells, which were assayed at various days in culture, the increase in [3H]NE accumulation per culture was less than that seen in freshly dissociated noncultured embryonic cells. When [H]NE uptake was expressed per mg protein, a decrease with days in culture was observed. reflecting perhaps a dilution of growth or proliferation of cells not accumulating NE. Metanephrine, 5 X 10(-6) M, an inhibitor of extraneuronal uptake, inhibited [3H]NE in 5-day-old cultures whereas desmethylimipramine, an inhibitor of neuronal uptake, inhibited [3H]NE uptake in 15- and 20-day-old cultures. Cocaine, another neuronal inhibitor, inhibited [3N]NE at 10 and 15 days only. We interpret these findings to suggest that during early growth in culture most neuroblasts accumulate NE nonspecifically and, as neuronal maturation proceeds, NE accumulation becomes specific.
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000196:embryology / Q000378:metabolism*; D002478:Cells, Cultured; D002642:Chick Embryo; D003042:Cocaine / Q000494:pharmacology; D003891:Desipramine / Q000494:pharmacology; D008676:Metanephrine / Q000494:pharmacology; D009638:Norepinephrine / Q000378:metabolism*; D013997:Time Factors
D008676:Metanephrine; D003042:Cocaine; D003891:Desipramine; D009638:Norepinephrine