Inhibitory Effect of Ethanol Administration on β-Alanine-2-Oxoglutarate Aminotransferase (GABA Aminotransferase) in Disulfiram-Pretreated Rats

Abstract

Ethanol in the presence of disulfiram (N, N, N', N'-tetra-ethylthiuram disulfide, an inhibitor of aldehyde dehydrogenase) inhib-ited liver β-alanine-oxoglutarate aminotransferase (β-AlaAT I) activity yet activated tyrosine aminotransferase (TAT) in weanlirrg rats in vivo. The effect on fi-AIaAT I was followed by the inhibitory expression of β-AIaAT I mRNA. The β-AIaAT I activity was reduced with a pseudo-first-order profile with time, and the half-life was calculated to be 12.3±0.83h with the rate constant (K_d) of 0.056±0.004h^-1. The synthesis of β-AIaAT Tin rat liver was estimated to be 1.56×10^-10 mol/g of wet tissue per hour at a steady state. A combination of ethanol and disulfiram also reduced β-alanine-pyruvate aminotransferase (β-AIaAT II) activity to 60% of the control after 24h.