Erythrocyte transketolase activity and guanidino compounds in hemodialysispatients

Background. The toxic effects of guanidino compounds on enzymatic activity in uremic patients are known. Thus, we determined the hemodialysis (I-ID) i mpact on this toxicity. Methods. The erythrocyte transketolase activity (ETKA), total guanidino com pounds (TGCs), and guanidinosuccinic acid (GSA) levels in plasma were compa red before, after 5 hours of I-ID, and at 12 and 24 hours from the end of H D. Thirty-seven HD patients (28 to 49 years old) with primary glomerulopath ies participated in this study. Thirty healthy volunteers (HVs) served as c ontrols. Results. 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 hig her (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 TID, the ETKA incre ased 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 an d 24 hours from the end of IID, the ETKA decreased to 2.25 +/- 0.56 and 2.0 9 +/- 0.49 (P < 0.001), respectively. The plasma levels for TCC and GSA bot h increased: TGC to 19.39 +/- 3.67 and 25.68 +/- 4.61 (P < 0.001), respecti vely; GSA to 3.49 +/- 1.11 and 4.53 +/- 1.12 (P < 0.001), respectively. Conclusion. There was no significant correlation between ETKA and the plasm a levels of the examined toxins. By removing the guanidino compounds, I-ID temporarily decreases the inhibition of ETKA, diminishing other metabolic d isturbances connected with pentose phosphate cycle.