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Long‐term adaptive response to dietary protein of hexose monophosphate shunt dehydrogenases in rat kidney tubules
Author(s) -
Peragón Juan,
Aranda Fermín,
GarcíaSalguero Leticia,
Vargas Alberto M.,
Lupiáñez José A.
Publication year - 1990
Publication title -
cell biochemistry and function
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 61
eISSN - 1099-0844
pISSN - 0263-6484
DOI - 10.1002/cbf.290080103
Subject(s) - pentose phosphate pathway , hexose , dehydrogenase , carbohydrate , endocrinology , medicine , glucose 6 phosphate dehydrogenase , enzyme , kidney , pentose , meal , phosphogluconate dehydrogenase , chemistry , biology , biochemistry , glycolysis , fermentation
We have studied the effects of several different macronutrients on the kinetic behaviour of rat renal glucose 6‐phosphate dehydrogenase (G6PDH) and 6‐phosphogluconate dehydrogenase (6PGDH). Rats were meal‐fed with high‐carbohydrate/low‐protein, high‐protein/low‐carbohydrate and high‐fat diets. High‐protein increased renal G6PDH and 6PDGH activities by 66 per cent and 70 per cent respectively, without significantly changing the K m values of either and each Hexose monophosphate dehydrogenase activity increased steadily, reaching a significant difference on day 4. A rise in carbohydrate or fat in the diets, produced no significant change in either the activity or the kinetic parameters, V max and K m of the two dehydrogenases. In addition, the administration of a high‐protein diet for 8 days significantly increased both the pentose phosphate pathway flux (92·6 per cent) and the kidney weight (35 per cent), whereas no significant changes in these parameters were found when the animals were treated with the other diets. Our results suggest that an increase in the levels of dietary protein induces a rise in the intracellular levels of these enzymes. The possible role of this metabolic pathway in the kidneys under these nutritional conditions is also discussed.