November 1970

Transketolase Activity in Uremia

Author Affiliations

New York

From the Renal Service and Laboratory, Departments of Medicine and Pediatrics, New York Medical College, New York.

Arch Intern Med. 1970;126(5):851-854. doi:10.1001/archinte.1970.00310110121021

Erythrocyte transketolase activity (ETKA) was determined in ten uremics undergoing long-term hemodialysis and in four patients treated with Giordano-Giovanetti diet therapy. Transketolase is an essential enzyme in the pentose phosphate shunt and plays a role in myelin sheath maintenance. Its co-factor is thiamine pyrophosphate. In thiamine deficient states ETKA is depressed. ETKA predialysis was depressed in six chronic uremics, although all received thiamine. Dialysis restored ETKA toward normal. Diet patients had depressed transketolase activity which was not affected by diet therapy despite reduced blood urea nitrogen levels. Uremic plasma inhibited normal ETKA by an average of 31.2%; inhibition was reversed by dialysis. A low weight molecular fraction (<500) obtained from dialysates of uremic subjects inhibited normal ETKA. Low weight dialyzable toxin(s) accumulates in the plasma of uremics, which inhibits ETKA and may play a role in the development of uremic polyneuropathy.