Evaluation of several saccharides as osmotic agent for peritoneal dialysate

The carbonyl group of glucose reacts non-enzymatically with the amino group of protein to form advanced glycosylation end-products (AGEs). AGEs are found in the peritoneum of continuous ambulatory peritoneal dialysis patients, and this AGE formation is suspected to be one of the causes of impaired peritoneal function. In order to control AGE formation in the peritoneum, AGE formation and ultrafiltration in rats were examined with peritoneal dialysates using as osmotic agents saccharides that lack a carbonyl group, the saccharic acid lactobionate [molecular weight (MW) 358.30], the sugar alcohol maltitol (MW 344.32), and the nonreducing sugar nistose (MW 666.58).

Bovine serum albumin (BSA) (25 mg/mL) was incubated with 18, 36, and 72 mg/mL maltitol, lactobionate, nistose, and glucose at 37 degrees C. After 3 or 6 weeks, amounts of furosine and N-(carboxymethyl) lysine were measured. A 20-mL intraperitoneal injection of a lactate-based dialysate (osmotic pressure 388 mOsm/kg) containing 4.34% maltitol, 4.52% lactobionate, or 8.4% nistose was given to Sprague-Dawley rats and, after 2, 4, or 6 hours, the quantity of effluent and levels of urea nitrogen and creatinine in the effluent and in serum were measured.

No increases in furosine or N-(carboxymethyl) lysine were seen with maltitol, lactobionate, or nistose after 3 and 6 weeks of incubation with BSA; AGE formation was not observed. In the study in rats, the quantity of abdominal fluid after a 6-hour dwell was nistose > lactobionate > maltitol > glucose. No differences in dialysate-to-plasma ratios for urea nitrogen or creatinine were seen in any group.

AGE formation in peritoneal tissue might be controlled by using saccharides with a modified carbonyl group as osmotic agents for peritoneal dialysates. Nistose is considered to yield the most efficient dialysis.