Abnormal Excretion of β-Aminoisobutyric Acid in Urine of the Rats Injected with 1-Aminoproline and Its Stereospecificity

Abstract

One of the unidentified ninhydrin positive substances abnormally excreted in urine of the rats injected with 1-aminoproline was characterized as β-aminoisobutyric acid. The absolute configuration of this amino acid was proved to be the (R)-form by means of a specific gas chromatographic technique. Excretion of (R)-β-aminoisobutyric acid reached a maximum during the interval from 3.5 to 5 hr after the intraperitoneal injection of 1-aminoproline. Spectacular accumulation of β-aminoisobutyric acid was observed in liver and kidney by the 1-aminoproline treatment. The amino acid accumulated in these tissues also had the (R)-form. These facts suggest that 1-aminoproline inhibits the stereospecific metabolism of the β-aminoisobutyric acid.