Erythrocyte transketolase activity and guandino compounds in hemodialysis patients

Abstract

The toxic effects of guanidino compounds on enzymatic activity in uremic patients are known. Thus, we determined the hemodialysis (HD) impact on this toxicity. The erythrocyte transketolase activity (ETKA), total guanidino compounds (TGCs), and guanidinosuccinic acid (GSA) levels in plasma were compared before, after 5 hours of HD, and at 12 and 24 hours from the end of HD. Thirty-seven HD patients (28 to 49 years old) with primary glomerulopathies participated in this study. Thirty healthy volunteers (HVs) served as controls. At the beginning of this study, ETKA was lower in uremics (1.94 +/- 0.45) than in HVs (2.59 +/- 0.26). The TGC and GSA plasma levels were higher (26.07 +/- 5.34 and 4.5 +/- 1.22) than in HVs (10.41 +/- 1.42 and 0.76 +/- 0.09, P < 0.001), respectively. After five hours of HD, the ETKA increased to 2.49 +/- 0.62 (P < 0.001). The plasma levels TGC decreased to 12.56 +/- 2.02 (P < 0.001) and the GSA to 2.12 +/- 0.68 (P < 0.001). After 12 and 24 hours from the end of HD, the ETKA decreased to 2.25 +/- 0.56 and 2.09 +/- 0.49 (P < 0.001), respectively. The plasma levels for TGC and GSA both increased: TGC to 19.39 +/- 3.67 and 25.68 +/- 4.61 (P < 0.001), respectively; GSA to 3.49 +/- 1.11 and 4.53 +/- 1.12 (P < 0.001), respectively. There was no significant correlation between ETKA and the plasma levels of the examined toxins. By removing the guanidino compounds, HD temporarily decreases the inhibition of ETKA, diminishing other metabolic disturbances connected with pentose phosphate cycle.