Expression of vascular endothelial growth factor, fibroblast growth factor, and lactate dehydrogenase by human peritoneal mesothelial cells in solutions with lactate or bicarbonate or both.

In patients on long-term continuous ambulatory peritoneal dialysis, the efficiency of dialysis declines because of peritoneal neovascularization and loss of peritoneal mesothelial cells. In this study, we investigated the influence of lactate and bicarbonate in peritoneal dialysis fluid on such changes of the peritoneum. We studied the production of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), which induce peritoneal neovascularization, by human peritoneal mesothelial cells (HPMCs) cultured with lactate or bicarbonate or both. Lactate dehydrogenase (LDH) was also measured to assess cell necrosis. Levels of VEGF, bFGF, and LDH in the culture supernatant showed a significant decrease after incubation of HPMCs with 15 mEq/L lactate plus 25 mEq/L bicarbonate, or with 40 mEq/L bicarbonate, as compared with incubation with 40 mEq/L lactate. Levels of VEGF and bFGF showed a concentration-dependent decrease when the cells were incubated with lactate or bicarbonate; a concentration-dependent increase of LDH was simultaneously observed. These results suggest that dialysis fluid containing 40 mEq/L bicarbonate is superior to fluid containing 40 mEq/L lactate with regard to its influence on the production of VEGF and bFGF although lactate and bicarbonate are both toxic for HPMCs.