The accumulation of DL-glutamate by the central nervous system of the snail Helix pomatia.
Isolated snail ganglia are capable of maintaining their free amino acid levels steady for the first 60 min of incubation in physiological saline. Within this time the ganglia also possess an uptake mechanism for DL-glutamate which can be divided into sodium-sensitive and -insensitive components. The accumulation of DL-glutamate showed saturation kinetics typical of a carrier-mediated process. The Vmax value for the uptake is 1.5 x 10(-8) mole/g/min and the Km value 1.1 x 10(-4) M. The amino acid accumulation is quite specific towards L-dicarboxylic acids and insensitive to a number of metabolic inhibitors. It is unlikely to be due to a homoexchange phenomenon because the ganglia are capable of achieving a net uptake of glutamate and the efflux of DL-[3H]glutamate is not increased by the addition of non-radioactive L-glutamate to the incubation medium.
D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D046508:Culture Techniques; D004573:Electrolytes / Q000494:pharmacology; D005724:Ganglia / Q000378:metabolism*; D005971:Glutamates / Q000008:administration & dosage / Q000378:metabolism*; D006372:Helix, Snails; D007700:Kinetics; D013696:Temperature; D014316:Tritium / Q000378:metabolism
D000596:Amino Acids; D004573:Electrolytes; D005971:Glutamates; D014316:Tritium