Characteristics of excitatory amino acid uptake in cultures from neurons and glia from the retina

✍ Scribed by F. Somohano; Dr. A. M. López-Colomé

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 678 KB
• Volume: 28
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490280412

✦ Synopsis

Abstract

^3^H‐D‐Aspartate uptake was biochemically characterized in cultures from chick retina enriched in glial (Müller) 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 μM 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 μM. In both cases, uptake wastemperature 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‐ β‐hydroxamate for inhibiting ^3^H‐D‐As‐partate uptake. Results suggest the possibility of re‐uptake participating in the regulation of extracellular glutamate concentration during development.