Is plasticizer toxic to peritoneal mesothelial cells?

The plasticizer di(2-ethylhexyl)phthalate (DEHP) used in peritoneal dialysate bags is known to dissolve into the solution, even though the quantity is small. Long-term exposure of the peritoneum to DEHP could be a cause of peritoneal deterioration. Although some papers have been published about DEHP toxicity to the peritoneum, acute DEHP toxicity is not fully understood to date. We therefore conducted the present in vitro study, using peritoneal mesothelial cells to examine acute DEHP toxicity. Peritoneal mesothelial cells were harvested from the peritonea of Sprague-Dawley rats and were cultured in Dulbecco modified eagle medium supplemented with 1% fetal calf serum. Confluent mesothelial cells were incubated with DEHP at various concentrations for 24 hours. The concentration of lactate dehydrogenase in the supernatant was measured and compared to control samples. In addition, apoptosis of mesothelial cells was examined by the TUNEL method at various concentrations of DEHP. We found that DEHP (260pmol/L to 2.6 mmol/L) neither elevated lactate dehydrogenate in the supernatant nor induced apoptosis of cultured mesothelial cells. The concentration of DEHP in peritoneal dialysate bags is reported to be approximately 20 nmol/L. Our results indicate that the plasticizer dissolved in dialysis solution from peritoneal dialysate bags does not have significant acute toxicity on peritoneal mesothelial cells. Furthermore, apoptosis may not be induced even after long-term and repeated use of solution from peritoneal dialysate bags.