Rando R R, Coburn J, Parkinson D
J Neurochem. 1982 Oct;39(4):1147-51. doi: 10.1111/j.1471-4159.1982.tb11508.x.
The inactivation of gamma-aminobutyrate (GABA)-transaminase by the highly specific and potent neurotoxin gabaculine leads to different neurochemical consequences in the chick brain as opposed to the chick retina. In the brain, GABA levels continually climb, reaching approximately eightfold increases over control values after 24 h. The elevation in GABA levels leads to a time-dependent and coincident fall in glutamate decarboxylase and cysteine-sulfinate decarboxylase activities, to approximately 50% of control values. On the other hand, in the retina GABA levels only increase to a plateau level two- to threefold that of control after inactivation of GABA-transaminase. Furthermore, although the glutamate decarboxylase activity decreases to about 50% of control values, cysteinesulfinate decarboxylase activity is not affected. These studies show that the processing of GABA in the retina differs from that in the brain, and that cysteinesulfinate and glutamate decarboxylase activity probably reside in different enzyme molecules in the retina, although they may reside in the same enzyme in the brain.
高特异性强效神经毒素加巴喷丁使γ-氨基丁酸（GABA）转氨酶失活，这在鸡脑中产生的神经化学后果与鸡视网膜不同。在脑中，GABA水平持续攀升，24小时后比对照值增加约8倍。GABA水平的升高导致谷氨酸脱羧酶和半胱氨酸亚磺酸盐脱羧酶活性随时间下降，降至对照值的约50%。另一方面，在视网膜中，GABA转氨酶失活后，GABA水平仅升高至对照值的两到三倍并达到稳定水平。此外，虽然谷氨酸脱羧酶活性降至对照值的约50%，但半胱氨酸亚磺酸盐脱羧酶活性不受影响。这些研究表明，视网膜中GABA的处理方式与脑中不同，并且半胱氨酸亚磺酸盐脱羧酶和谷氨酸脱羧酶活性在视网膜中可能存在于不同的酶分子中，尽管它们在脑中可能存在于同一种酶中。
