A commercially available PD fluid with high pH and low GDP induces different morphological changes of rat peritoneum...

The aim of this study was to characterize the morphological changes in the peritoneum following experimental peritoneal dialysis of rats, and to compare the new high-pH and low glucose-derived degradation products (GDP)-level PD fluid PD-Bio with the conventional PD fluid Gambrosol at two different exposure frequencies. Rats were subjected to 10 mL intraperitoneal injections three times per day at 3-hour intervals daytime for 9 days (2 successive weeks, excluding weekends) or once daily for 4 weeks. Untreated animals and animals exposed to Gambrosol or PD-Bio were compared. Biopsy samples were taken from the diaphragm and prepared for light microscopy. Morphometric analysis was used to compare the thickness and the cell density of the sub-mesothelial connective tissue. Intraperitoneal leukocyte numbers were counted. Both fluids induced a significant thickening of the submesothelial connective tissue and an increase in intraperitoneal leukocyte numbers. After exposure three times per day, Gambrosol induced a significantly greater submesothelial thickening than PD-Bio. The submesothelial tissue was more cell-dense after exposure to PD-Bio than after exposure to Gambrosol. The present results indicate that the structural changes of the peritoneum that follow peritoneal dialysis may be dependent upon the chemical composition of the PD fluids.