Effect of Pathological Conditions on Transamination

According to S. Kaplansky (9Sa), the reaction GL— AL is markedly depressed (in parallel with lowered activity of other engymes) in the liver, ki ey and muscles of hypoproteinemic rats, maintiuned on a protdn-deficient diet. After trantition to a high-protein diet restitution is very slow. 

One instance is known of more or less specific patholojpcal disturbance of transamination, namely, the marked decrease in -aph and as-aph activity in all tissues of severely thiamine-deficient pigeons and rats, described by Kritzmann (118, 119) the rates of l amino acid deamination and of re-ductive amination of PU are similarly lowered, while the activity of d-amino acid oxidase and of glutamic dehydrogenase is not impiured. Absence of these effects in starved controls and the rapid restoration of aph activity upon administration of thiamine rule out a non-specific effect of lowered protein intake. 

Barron and associates (12) found no activation of transamination on addition of thiamine tn vitro to minced tissues from thiamine-deficient animals, but the experimental conditions were such as to preclude the synthesis of diphosphothiamine. Cohen (61) mentions unpublished results confirming the data of Kritzmann. The decrease of amino-pherase activity in pyridoxme-deficient rats has been mentioned on page 14. 

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