Characteristics of excitatory amino acid uptake in cultures from neurons and glia from the retina
Por:
Somohano F., López-Colomé A.M.
Publicada:
1 ene 1991
Resumen:
3H-D-Aspartate uptake was biochemically characterized in cultures from chick retina enriched in glial (Muller) cells or neurons during progressive days in vitro (DIV). In the neuronal cultures a high-affinity, Na+-dependent system was found with Km = 8-13 ?M and pharmacological characteristics in agreement with those of reuptake systems in other regions of the CNS. The uptake system in glial cells showed a lower affinity, with Km = 100-135 ?M. In both cases, uptake was temperature and energy dependent. A sharp increase in the V(max) of uptake was observed in both neuronal and glial cultures at 5 DIV, at which time morphologically mature synapses have been shown to be present in retinal cultures. A parallel increase in the pharmacological specificity of the uptake system in neuronal cultures was observed, with a rise in the efficiency of D-Asp, L-Asp, L-Glu, and DL-asp- ?-hydroxamate for inhibiting 3H-D-Aspartate uptake. Results suggest the possibility of reuptake participating in the regulation of extracellular glutamate concentration during development.
Filiaciones:
Somohano F.:
Departamento de Neurociencias, Instituto de Fisiología Celular, UNAM, México, Distrito Federal, Mexico
López-Colomé A.M.:
Departamento de Neurociencias, Instituto de Fisiología Celular, UNAM, México, Distrito Federal, Mexico
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