Does glucose present in the dialysate limit oxidative stress in patients undergoing regular hemodialysis?
BACKGROUND
Decreased glucose concentration in the blood causes the inhibition of the hexose monophosphate (HMP) cycle in the erythrocyte. NADPH, which is the source of the reductive equivalents necessary for the reproduction of glutathione (GSH), is not regenerated. The presence of glucose in dialysate should provide the stability of its concentration in the blood of patients undergoing hemodialysis (HD). The aim of the study was to assess the influence of glucose in the dialysate on the intensity of oxidative stress in patients undergoing regular HD.


METHODS
The study comprised 43 patients hemodialyzed with dialysate containing (HD-g(+)) or not containing glucose (HD-g(-)). The concentrations of the products of reaction with thiobarbituric acid-reactive substance (TBARS) and GSH as well as the activity of erythrocyte superoxide dismutase were determined. Glucose concentrations in the blood before and immediately after dialysis were also measured.


RESULTS
After flow-through dialysis the glucose concentration in the blood decreases both when dialysate does not contain glucose (4.8 vs. 1.6 mmol/l) and when dialysate contains glucose (6.6 vs. 5.8 mmol/l). HD caused changes in the TBARS concentration: in the HD-g(+) group the concentration decreased after HD, whereas in the HD-g(-) group it increased. In both groups of patients studied the GSH concentration changed after HD; in the HD-g(-) group it decreased and in the HD-g(+) group it increased. The results obtained in the groups of patients examined were confirmed by in vitro studies.


CONCLUSIONS
The presence of glucose in the dialysate guarantees the normal activity of the HMP cycle, which provides the production of reductive equivalents for the regeneration of reduced GSH - free radicals scavenger - and therefore the limitation of oxidative stress.
Bober
Joanna
J
Department of Chemistry and Biochemistry, Transplantology and Internal Medicine, Pomeranian Medical University, PL-70-111 Szczecin, Poland. jbober@sci.pam.szczecin.pl
Kwiatkowska
Ewa
E
Kedzierska
Karolina
K
Olszewska
Maria
M
Dolegowska
Barbara
B
Domanski
Leszek
L
Herdzik
Edyta
E
Ciechanowski
Kazimierz
K
Chlubek
Dariusz
D
D000368:Aged; D015314:Dialysis Solutions / Q000008:administration & dosage*; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects*; D010427:Pentose Phosphate Pathway / Q000187:drug effects; D006435:Renal Dialysis
D015314:Dialysis Solutions; D005947:Glucose