R. S. Krooth, Hsiao Wen-Luan, George F.M. Lam
Apr 1, 1979
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0
Influential Citations
11
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Quality indicators
Journal
Biochemical pharmacology
Abstract
Abstract 6-Azauracil, which is reported to have an hypnotic effect in man, rat and mouse, is a noncompetitive inhibitor of gamma-aminobutyric acid (GABA)-transaminase activity in rodent and human brain extracts. The Ki for the rat brain activity is 5 × 10−4 M. GABA-transaminase is also non-competitively inhibited by a number of other compounds-both drugs and natural substances—which are reported to affect arousal and which, like 6-azauracil, include within their structure a pyrimidine or pyrimidine-like ring. None of these compounds, however, is as potent an inhibitor of the transaminase as 6-azauracil. Glutamic acid decarboxylase is inhibited only weakly (and non-competitively) by 6-azauracil and, to an even lesser extent, by the other substances tested. None of the compounds under study caused appreciable inhibition of DOPA decarboxylase except under conditions where the enzyme proved highly unstable, and even under these conditions the inhibition was weak.