Prolonged preservation of rat peritoneal mesothelial cells (RPMC) and rat peritoneal fibroblasts (RPFB) with neutral pH peritoneal dialysis solution depleted of glucose degradation products (GDPs)

Abstract

Background. In-vitro biocompatibility tests were conducted to verify the assumption that glucose degradation products (GDPs) and pH could be factors that reduce peritoneal cell viability. Methods. Peritoneal mesothelial cells and fibroblasts isolated from the omentum of male Wistar rats were used in all experiments. Peritoneal dialysis solutions (PDSs) to be tested varied in GDP content, pH, and glucose concentration (1.36%, 2.27%, and 3.86%). Subconfluent cells were exposed to the dialysis solutions over time courses of 30 min to 6 h. Cell viability was assessed by MTT evaluation and the gene expression of interleukin 6 (IL-6) was determined by reverse transcription (RT)-polymerase chain reaction (PCR). Peritoneal dialysis solutions (PDSs) tested were: (I) PDS autoclaved (PDS-AC), neutral pH, +GDP; (II) PDS filtered (PDS-Filt), neutral pH, −GDP; (III) Gambrosol autoclaved (Gsol-AC), acidic pH, ++GDP; and (IV) Gambrosol filtered (Gsol-Filt), acidic pH, −GDP. Results. After 30-min exposure to the dialysis solutions, cell viability was greatest in cells exposed to group II solutions, followed by groups I, IV, and III. With increased exposure time (6 h), this difference in viability was further enhanced, showing that cells exposed to high GDP and acidic pH had a significant reduction in viability as compared with cells exposed to low GDP and neutral pH. The expression of IL-6 mRNA in mesothelial cells was much more susceptible to pH than this expression in peritoneal fibroblasts, as was also seen in the MTT evaluation. Conclusions. These results indicate that dialysis solutions with neutral pH and low GDP content provide a more biocompatible environment than dialysis solutions with acidic pH and high GDP content in which to maintain the viability of resident peritoneal cells.