Efficiency of hemodialysis of pyrimidine compounds in patients with chronic renal failure.

The accumulation in blood plasma and efficiency of hemodialysis of pyrimidine compounds (orotic acid, orotidine, pseudouridine, uridine, thymine) as well as uric acid and creatinine in 23 patients with chronic renal failure (CRF) was investigated. As a reference, the analysis of the above metabolites in the plasma of 30 healthy volunteers was performed. Among examined compounds, pseudouridine possessed the highest capability of accumulation in blood plasma (25 times higher concentration than physiological). It coincided with the lowest efficiency of pseudouridine hemodialysis (44%) and the longest T1/2 (relative to creatinine) in plasma. A significant linear correlation (r = 0.81, p < 0.001) between efficiency of creatinine and pseudouridine hemodialysis was calculated. The concentration of orotic acid in the blood plasma of patients before hemodialysis exceeded 14 times its level in healthy subjects; the inhibition of uric acid synthesis by allopurinol in dialyzed patients was accompanied by enlargement of orotidine and orotate accumulation in blood plasma. Extremely high plasma concentration of examined pyrimidines remaining elevated after hemodialysis creates an additional hazard for tissue metabolism and health of patients with CRF.