In vitro effects of amino-acid-based versus glucose-based continuous ambulatory peritoneal dialysis fluids on peritoneal macrophage function.
We studied the in vitro effects of peritoneal dialysis fluids (PDF) containing 1 and 1.5% amino acids (AA) as compared to approximately equiosmolar glucose (GLU)-based PDF (1.5 and 4.25%) and control buffer, respectively, on peritoneal macrophage (PMO) function. The media were tested at original pH (5.3-5.5) and after pH adjustment to 7.4. PMO were isolated from the effluents of 10 on continuous ambulatory peritoneal dialysis (CAPD) patients and tested for luminol- and lucigenin-enhanced chemiluminescence (CL), superoxide generation measured by cytochrome c reduction, killing capacity and phagocytosis after incubation (30 min, 37 degrees C) in the PDF used. All AA-based PDF exhibited a statistically significant depressive effect on integral CL response, O2- production and bacterial killing of PMO at pH 7.4 in comparison with pH-adjusted GLU-based PDF of similar osmolality and buffer. Exposure of PMO to acidic AA-based media did not result in a significantly different suppression of the oxidative metabolism and the killing capacity as compared to fresh GLU-based fluids. Phagocytosis of PMO did not show significant differences after incubation in the solutions studied. Thus, the AA-based PDF employed compromise the oxidative metabolism and the killing capacity of PMO at pH 7.4 in vitro significantly more than GLU-based fluids. Since pH-identical and almost equiosmolar PDF were compared, the specific composition of the AA-based fluids, especially the high content of lactate and several essential AA, could be responsible for this detrimental impact.
Department of Internal Medicine, Robert Bosch Hospital, Stuttgart, Deutschland.
U
U
Schenk
T
T
Kiefer
E
E
Hübel
J
J
Weber
T
T
Mettang
J
J
Passlick-Deetjen
U
U
Kuhlmann
D000596:Amino Acids / Q000494:pharmacology*; D001433:Bacteriolysis / Q000502:physiology; D015314:Dialysis Solutions / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007676:Kidney Failure, Chronic / Q000473:pathology* / Q000628:therapy; D008163:Luminescent Measurements; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D010531:Peritoneal Dialysis, Continuous Ambulatory; D010587:Phagocytosis / Q000502:physiology; D016897:Respiratory Burst / Q000502:physiology; D013481:Superoxides / Q000378:metabolism
D000596:Amino Acids; D015314:Dialysis Solutions; D013481:Superoxides; D005947:Glucose