title: Organic aciduria in rats fed high amounts of xylitol or sorbitol.
abstract: The acidification of urine during polyol feeding was investigated with 27 Long-Evans male rats (aged 12 weeks) which were fed a xylitol diet (X), a sorbitol diet (S), or a basal diet for 4 weeks. The amount of polyols in the diet was increased from 5% to the final 20% level within 3 weeks. The polyol-fed animals showed reduced weight gain, lowered urine pH (from 6.5 to 5.6), and a 4-fold increase in the titratable acid excretion. X and S increased the daily urine volumes by 49 and 63%, respectively, but did not affect the wet weight or the pH values of the feces. as chromatographic-mass spectrometric analyses of organic acids revealed highly increased amounts of methylmalonic acid (13- to 20-fold) and 2-oxoglutaric acid (4- to 5-fold) in the urine of polyol-fed rats. The urinary excretion of citric acid and malic acid was also increased significantly (2- to 4-fold). The acidity of urine was not reflected in the blood acid-base balance of the animals. The increases in the levels of urinary organic acids in the polyol-fed rats were explained in terms of impaired mitochondrial oxidation of these acids and of impaired conversion of methylmalonic acid to succinic acid.
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002951:Citrates / Q000652:urine*; D019343:Citric Acid; D003593:Cytoplasm / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D007656:Ketoglutaric Acids / Q000652:urine*; D008293:Malates / Q000652:urine*; D008297:Male; D008314:Malonates / Q000652:urine*; D008764:Methylmalonic Acid / Q000652:urine*; D009243:NAD / Q000032:analysis; D010070:Oxalates / Q000652:urine; D019815:Oxalic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D013012:Sorbitol / Q000633:toxicity*; D014993:Xylitol / Q000633:toxicity*
chemical_list: D002951:Citrates; D007656:Ketoglutaric Acids; D008293:Malates; D008314:Malonates; D010070:Oxalates; D009243:NAD; D019343:Citric Acid; D013012:Sorbitol; C030298:malic acid; D008764:Methylmalonic Acid; D019815:Oxalic Acid; D014993:Xylitol