Studies on the effect of low-molecule uremic toxins on the activity of glucose-6-phosphate dehydrogenase (E.C.1.1.1.49) and transketolase (E.C.2.2.1.1) in human red blood cells.

The effect in vitro was studied of methylguanidine (MG) and guanidinosuccinic acid (GSA) on the activity of glucose-6-phosphate dehydrogenase (G-6-P DH) and transketolase (ETKA) of normal erythrocytes. The results show that MG in concentration (1.8 X 10(-5) mol/l) approximate to or higher then its concentration in plasma of patients with chronic renal failure (ch.r.f.) inhibits the activity of G-6-P DH. The changes of similar nature have been observed in case of GSA. In the same incubation conditions MG or GSA bring about the inhibition of ETKA activity in red blood cells. MG and GSA jointly introduced into incubation mixture in concentrations approximate to those appearing in plasma of patients with ch.r.f. cause the inhibition of G-6-P DH by 35.6% on the average, with no statistically significant differences in ETKA activity.