Glycosuria renal

Carbohydrate abnormalities, such as renal glycosuria (a transport defect), pentosuria (enzyme deficiency, xylitol dehydrogenase I. lactase deficiencies, fructose intolerance, galactosemia, galacloki-nase deficiency, oxalosis, and several glycogenoses (von Gierke s, Forbes . Andersen s, Hers s. and Tarui s diseases). 

H9. Harrison, H. E., and Harrison, H. C., Experimental production of renal glycosuria, phosphaturia, and aminoaciduria by injection of maleic acid. Science 120, 606-608 (1954). 

M3. McCune, D. J., Mason, H. H., and Clarke, H. T., Intractable hypophospha-temic rickets with renal glycosuria and acidosis (the Fanconi syndrome). Report of a case in which increased urinary organic acids were detected and identified, with a review of the literature. Am. J. Diseases Children 66, 81-146 (1943). 

An 18-year-old woman presented with new onset seizures and polydipsia. She had a hyponatremia of 117 mmol/1, polyuria for several hours, renal glycosuria with urine glucose of over 55 mmol/1, a blood glucose of 6.6 mmol/1, and solute diuresis. She had low tubular reabsorption of phosphorus, with an appropriate transtubular potassium gradient of 3.0 and a serum potassium of 3.7 mmol/1. After medical treatment and gradual correction of her hyponatremia, her tubular... 

The carbohydrate analyzer has shown that there are considerable differences in excretion patterns of carbohydrates in disease. Many carbohydrates are excreted in excess in renal glycosuria and diabetes mellitus (Yl). Other abnormalities, such as pancreatic insufiSciency and lactose deficiency, show several carbohydrate excretion abnormalities. The presence of large amounts of xylulose and other sugars during ingestion of xylose indicates that the xylose tolerance test may not be a true measurement of absorption since that sugar apparently also metabolizes (Yl). 

Finally, functional tubular changes have also been described. Renal glycosuria, either with [18] or without [19] a fall in GFR has been found during treatment with captopril. In both cases the abnormality disappeared after withdrawal of the drug. 

Abnormal values of fractional lithium excrehon have been reported in a variety of condihons. In hyperthyroidism and Bartter s syndrome frachonal lithium clearance is increased. After unilateral nephrectomy, lithium clearance by the remaining kidney increases. After two weeks, frachonal lithium clearance returns to normal. Rombola et al. [8] reported markedly increased frachonal lithium clearance values in pahents with Fan-coni syndrome, renal glycosuria, and hypercalciuria. 

L3. Leaf, A., The syndrome of osteomalacia, renal glycosuria, aminoaciduria, and increased phosphorus clearance (the Fanconi syndrome). In The Metabolic Basis of Inherited Disease (J. B. Stanbury, J. B. Wyngaarden, and D. S. Fredrickson, eds.), 2nd Ed., pp. 1205-1220. McGraw-Hill, New York, 1966. 

Fig. 4 Urinary urate excretion in mother and her son, with renal glycosuria, at increasing levels of plasma glucose.

To evaluate the benefit of the various carbohydrates, we looked at their metabolic effects under conditions of extreme hepatic gluconeogenesis. This involved the use of phlorizin diabetes first studied by Graham Lusk sixty years ago (1912). Phlorizin blocks renal tubular reabsorption of glucose, leads to renal glycosuria which results in gluconeogenesis. We administered phlorizin by means of continuous intravenous infusion with or without added carbohydrates. 

Swift, RG.F. and Schaub, J. (2001) Mutations in SGLT2, the gene for a renal sodium/ glucose cotransporter, in patients with renal glycosuria. Submitted for publication. 

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