title: The biosynthesis and content of gamma-aminobutyric acid in the goldifsh retina.
abstract: Goldfish retinas incubated with L-glutamate-(14)C (UL) were found to synthesize gamma-aminobutyric acid-(14)C (GABA-(14)C) The accumulation of newly synthesized GABA was enhanced by physiological stimulation of the retina with flashing light; and this increase was directly proportional to the logarithm of the light intensity. The total GABA content was also higher in light-stimulated than in dark-adapted retinas, although the glutamate content remained unchanged No differences were found in the cell-free activities of glutamate decarboxylase (EC 4 1.1 15) and GABA-glutamate transaminase (EC 2.6.1.19) extracted from light-stimulated and dark-adapted retinas. These findings, together with other physiological and morphologcal evidence, suggest that GABA plays a functional role in synaptic transmission in the goldfish retina
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000613:Aminobutyrates / Q000032:analysis / Q000096:biosynthesis* / Q000502:physiology; D000818:Animals; D002247:Carbon Isotopes; D002262:Carboxy-Lyases / Q000378:metabolism; D002474:Cell-Free System; D003530:Cyprinidae / Q000502:physiology*; D003623:Dark Adaptation; D004590:Electrophoresis, Paper; D005971:Glutamates / Q000378:metabolism; D007700:Kinetics; D008027:Light; D010775:Photic Stimulation; D011830:Radiation Effects; D012160:Retina / Q000201:enzymology / Q000378:metabolism*; D009435:Synaptic Transmission; D000637:Transaminases / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000613:Aminobutyrates; D002247:Carbon Isotopes; D005971:Glutamates; D000637:Transaminases; D002262:Carboxy-Lyases