Antioxidant mechanisms in human peritoneal mesothelial cells (HPMC) exposed in vitro to the constituents of dialysis fluid

摘要

Objective: To assess effects of hyperosmolarity, high glucose concentration, and low pH with or without lactate sodium at the level of antioxidant mechanisms, such as the concentration of total intracellular glutathione (GSH/GSSG), the activity of catalase (CAT) and total superoxide dismutase (SOD) in mesothelial cells (MC) in vitro.Methods: HPMC were obtained from omentum from nonuremic donors. The effect of pH (5.2-7.3) with or without sodium lactate (35 mM/L) was tested in Earle's salt after 30 min exposure, whereas the osmotic and metabolic effects of glucose, glycerol, mannitol, and amino acids were studied in a medium with 10% FCS after 4, 24, 72 and 104 h of exposure. The activity of antioxidant mechanisms was determined by spectrophotometry.Results: In the cells exposed to Earle's salt pH 5.2 with lactate, the GSH/GSSG level, and CAT and SOD activity were substantially reduced. After 4 h of exposure, glycerol, glucose and mannitol increased the GSH/GSSG content in MC; after 24 h only glucose slightly increased the GSH/GSSG level.Conclusion: We conclude that although low pH with high lactate concentration decreased the activity of all studied antioxidant mechanisms in MC, the clinical relevance of these observations needs to be studied further.Abbreviations: MC - mesothelial cells; GSH/GSSG - total intracellular glutathione; CAT - catalase; SOD - superoxide dismutase; FCS - fetal calf serum; PD - peritoneal dialysis.key words: peritoneal dialysis, inflammation, mesothelial cells, osmotic agents, antioxidants