EFFECT OF PERITONEAL-DIALYSIS EFFLUENT ON SUPEROXIDE ANION PRODUCTIONBY POLYMORPHONUCLEAR NEUTROPHILS

Peritoneal dialysis effluent (PDE) contains at least 2 factors capable of affecting superoxide generation by polymorphonuclear neutrophils ( PMN) in response to both particulate and soluble stimuli. A low molecu lar weight fraction (<1.2 kD) enhanced the response to the chemotactic peptide fMLP and to preopsonised Staphylococcus epidermidis and Candi da guilliermondii. A higher molecular weight fraction (>1.2 kD) inhibi ted superoxide production in response to phorbol myristate acetate (PM A). The effects of PDE were dose dependent over the range of 10-70% (v /v) and simply augmented and reduced the dose-response curve to fMLP a nd PMA, respectively. There was no alteration in the concentration of stimulus required to give maximal superoxide production in either case . These data suggest that factors capable of affecting superoxide prod uction by PMN accumulate in uraemia and are removed from the circulati on into dialysis fluid.