Renal fructose-metabolizing enzymes: significance in hereditary fructose intolerance

In patients with hereditary fructose intolerance, which is characterized by deficient aldolase activity toward fructose-1-phosphate, fructose induces a renal tubular dysfunction that implicates only the proximal convoluted tubule. Because normal metabolism of fructose by way of fructose-1-phosphate requires fructokinase, aldolase "B," and triokinase, the exclusively cortical location of these enzymes indicates that the medulla is not involved in the metabolic abnormality presumably causal of the renal dysfunction.