The uptake of gamma-aminobutyrate by organotypic cultures of chick spinal cord.
1. Explants of spinal cord from 10-day chick embryos maintained for up to 16 days in culture rapidly accumulated gamma-amino[(3)H]butyrate when incubated at 25 degrees C or 36 degrees C in a medium containing 50nm-gamma-aminobutyrate. The mechanism of the uptake process has many of the properties of an active-transport system: it is Na(+)-dependent, temperature-sensitive, inhibited by ouabain, and displays saturation kinetics. The apparent K(m) for gamma-aminobutyrate is 1.7x10(-5)m, and V(max.) is 33pmol/min per g. 2. The rate of accumulation of gamma-amino[(3)H]butyrate in cultures between the ages of 3 and 16 days was remarkably constant and was not related to the morphological maturity of the spinal-cord explants. 3. The present demonstration in spinal-cord explants of an active transport system for gamma-aminobutyrate, already established for non-cultured nervous tissue, means that nervous-tissue culture can provide a convenient model for studying uptake processes in the central nervous system.
D000613:Aminobutyrates / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active; D002642:Chick Embryo; D007700:Kinetics; D009924:Organ Culture Techniques; D010042:Ouabain / Q000494:pharmacology; D010100:Oxygen; D011312:Pressure; D012964:Sodium / Q000494:pharmacology; D013116:Spinal Cord / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D014316:Tritium
D000613:Aminobutyrates; D014316:Tritium; D010042:Ouabain; D012964:Sodium; D010100:Oxygen