ACCUMULATION OF INDOXYL-BETA-D-GLUCURONIDE IN UREMIC SERUM - SUPPRESSION OF ITS PRODUCTION BY ORAL SORBENT AND EFFICIENT REMOVAL BY HEMODIALYSIS

We identified and quantified indoxyl-beta-D-glucuronide in uremic seru m and urine to determine the metabolism of indoles including indoxyl s ulfate in uremic patients. Serum levels of indoxyl-beta-D-glucuronide were markedly increased in undialyzed uremic patients, in patients on hemodialysis, and in patients on continuous ambulatory peritoneal dial ysis. Urinary excretion of indoxyl-beta-D-glucuronide was also increas ed in undialyzed uremic patients. Urinary indoxyl-beta-D-glucuronide w as significantly correlated with serum indoxyl sulfate, indicating tha t a high serum level of indoxyl sulfate leads to the enhanced synthesi s of indoxyl-beta-D-glucuronide. Oral sorbent (AST-120) administration markedly decreased the serum and urine levels of indoxyl-beta-D-glucu ronide as well as indoxyl sulfate in the undialyzed uremic patients. S erum indoxyl-beta-D-glucuronide could be efficiently removed by hemodi alysis despite its high protein-binding ratio of about 50%. In conclus ion, the serum level of indoxyl-beta-D-glucuronide increases in uremic patients due to renal insufficiency and its increased production. The production of indoxyl-beta-D-glucuronide can be suppressed by oral so rbent treatment, and serum indoxyl-beta-D-glucuronide can be efficient ly removed by hemodialysis.