Pig muscle aldehyde reductase. Identity of pig muscle aldehyde reductase with pig lens aldose reductase and with the low Km aldehyde reductase of pig brain and pig kidney.

A monomeric (Mr = 43,000) NADPH-dependent oxidoreductase with a broad substrate specificity for aliphatic and aromatic aldehydes and aldo sugars has been purified from the skeletal muscle of female and castrated pigs. The properties of this enzyme are consistent with those of aldose reductase (EC 1.1.1.21), and the enzyme is immunologically identical with aldose reductase from pig lens. However, antiserum to pig muscle aldehyde reductase also cross-reacts identically with the low Km aldehyde reductase from pig brain and kidney and the pattern of inhibition of the muscle reductase by anticonvulsant drugs is the same as that obtained for the low Km reductase. These intraspecies results yield the first definitive evidence that pig muscle aldehyde reductase is the same enzyme as aldose reductase and that the latter is identical with the low Km aldehyde reductase, one of two major aldehyde reductases found in mammalian tissues.