Decreased alanine aminotransferase activity in serum of man during γ-acetylenic-GABA treatment

Abstract

Decreasing concentrations of alanine aminotransferase were observed in nine patients receiving γ-acetylenic-GABA, an inhibitor of GABA aminotransferase. In vitro studies showed that preincubation at 37°C of serum with γ-acetylenic-GABA and with urine from a patient receiving the drug led to inhibition of alanine aminotransferase. This inhibition of alanine aminotransferase by γ-acetylenic-GABA was neutralized by 1-analine, the natural substrate for the enzyme. The mechanism of inhibition may be a competition between the drug and 1-alanine for the substrate binding site of the enzyme.

Key Words:

• alanine aminotransferase
• drug interference
• Nordic Recommended Enzyme Methods
• substrate competition