Pyruvate preserves neutrophilic superoxide production in acidic, high glucose-enriched peritoneal dialysis solutions

To investigate effects of pyruvate (Py)-based peritoneal dialysis solutions (P-PDS) on neutrophilic superoxide (O2-) production against high glucose (HG) concentrations at acidic or physiologic pH value, and explore potential mechanisms.

Human neutrophils were incubated with both dl-lactate (La, 40 mM)-based PDS (L-PDS) and equimolar P-PDS at various pH and HG levels, respectively. Hanks' balanced salt solution (HBSS) served as controls. O2- generation was determined by the reduction of ferricytochrome c.

Acidic pH and high La induced acute and substantial inhibitions of O2- production. HG in both PDS and HBSS resulted in a suppression of O2- in a dose-dependent manner. P-PDS generated near twofold O2- formation of L-PDS counterparts at various pH and HG levels. P-PDS with HG produced significantly more O2- than Py-free HBSS counterparts.

Py in PDS effectively protected neutrophils from HG-induced inhibition of O2- production, even at a physiological pH. The Py cytoprotection may be associated with the preservation of carbohydrate metabolic pathways in addition to its alkalization.