Effects of chondroitin sulphate on fluid and solute transport during peritoneal dialysis in rats

The effect of chondroitin sulphate (CS) on peritoneal fluid and solute transport was studied in rats undergoing peritoneal dialysis. In the presence of CS, net ultrafiltration increased, while absorption of glucose and horseradish peroxidase from the peritoneal cavity decreased. Albumin, used instead of CS, did not modify either fluid or solute transport. In in vitro experiments on isolated rabbit mesentery, CS decreased transmembrane water flow induced by hydrostatic pressure, and its effect was not fully reversed 60 minutes after 'wash-out' of this glycosaminoglycan. We postulate that the polyanionic CS molecules are trapped in the peritoneal interstitium, thus decreasing its hydraulic conductivity and permeability, which in turn increases net fluid removal during peritoneal dialysis because of its slower absorption from the peritoneal cavity.