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Membrane‐bound sorbitol dehydrogenase in human red blood cells. Studies in normal subjects and in enzyme‐deficient subjects with congenital cataracts
Author(s) -
Alvarez A.,
Martínez A.,
Ibarra B.,
Medina C.,
Bracamontes M.,
Perea J.,
Vaca G.
Publication year - 1993
Publication title -
journal of inherited metabolic disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 102
eISSN - 1573-2665
pISSN - 0141-8955
DOI - 10.1007/bf00711317
Subject(s) - sorbitol , sorbitol dehydrogenase , galactitol , xylitol , nad+ kinase , fructose , biochemistry , ribitol , dehydrogenase , enzyme , galactosemia , red blood cell , red cell , medicine , chemistry , polyol pathway , endocrinology , biology , aldose reductase , galactose , fermentation
Summary Membrane‐bound and soluble forms of erythrocyte sorbitol dehydrogenase (SORD) activity are compared in normal individuals. Both isoenzymes showed similar properties. In a family with red cell SORD deficiency and congenital cataracts, K m values for sorbitol and NAD + as well as the effect of the enzymatic deficiency on sorbitol accumulation in red cells incubated in high‐glucose or high‐fructose media were determined. In SORD‐deficient patients, the enzymatic deficiency was observed in both crude haemolysate and SORD‐M preparations with sorbitol, galactitol, xylitol or ribitol as substrates. The mutation responsible for SORD deficiency did not modify the K m for sorbitol and NAD + . Finally, SORD deficiency produced a significant increase of sorbitol accumulation in red cells incubated in high‐concentration glucose media and a significant decrease when the cells were incubated in high‐concentration fructose media.