Kinetics and dose response of the effects of heated glucose peritoneal dialysis fluids on the respiratory burst of rat peritoneal leukocytes

Heat sterilization of glucose containing peritoneal dialysis (PD) fluids in duces the production of cytotoxic glucose degradation products (CDPs), some of which are still unidentified. The present study was performed to charac terize the kinetics and the dose-response of the respiratory burst inhibiti on of CDPs and to compare different fluids in this respect. The zymosan-ind uced respiratory burst of rat peritoneal neutrophils and macrophages was me asured by chemiluminescence (CL) after incubation in vitro for 1, 2, and 4 hours in different homemade and commercially available PD fluids, followed by one hour of recovery in Hanks' buffer. Heat sterilized fluids were compa red with their filter sterilized equivalents at two different pH levels. Th e results revealed that the inhibitory effect of heat sterilized fluids on the respiratory burst of peritoneal neutrophils is additive to that of low pH, but more fast-acting and, in contrast to the pH effect, similar in magn itude to its in vivo equivalent. The effect developed within 1 hour and had a linear dose response. The low CDP fluid Gambrosol-Bio was less toxic tha n the conventional fluid Gambrosol, but the difference was smaller than exp ected in relation to measured concentrations of known GDPs. Macrophages wer e less sensitive than neutrophils to the CDP effect.