The cytotoxicity of continuous ambulatory peritoneal dialysis solutions with different bicarbonate/lactate ratios

Five different bicarbonate-based continuous ambulatory peritoneal dialysis (CAPD) solutions (pH: 7.0-7.4; bicarbonate: 10-27 mM; lactate: 20.8-6.7 mM) were produced in order to examine the cytotoxic effects of the different compositions. The migratory capacity of normal human polymorphonuclear (PMN) granulocytes after exposure to the solutions was used as a cytotoxicity assay. All the tested solutions reduced cellular function compared to a standard cell culture medium, but considerable differences between the solutions were observed. The optimal conditions for the PMN migration were at a pH of 7.0 and at bicarbonate and lactate concentrations of 20 mM and 12.5 mM, respectively. Bicarbonate concentrations of more than 25 mM were associated with reduced cellular function as were lactate concentrations of more than 15 mM. The most advantageous CAPD solution regarding cytotoxicity towards normal human PMN's is a combination of a lactate and bicarbonate-based solution, which has a bicarbonate concentration of approximately 20 mM, a lactate concentration of 12.5 mM, and a pH of approximately 7.2.