Liquid-chromatographic profiling of solutes in serum of uremic patients undergoing hemodialysis and chronic ambulatory peritoneal dialysis (CAPD); high concentrations of pseudouridine in CAPD patients.

Abstract

Using "high performance" liquid chromatography, we studied non-protein-bound fractions and total concentrations of 18 solutes accumulating in sera from a group of 12 patients who were undergoing chronic ambulatory peritoneal dialysis (CAPD) and in predialysis sera from a group of 15 hemodialysis (HD) patients. We monitored longitudinal changes in solute concentrations for two patients with respect to change of therapy between HD and CAPD. The concentrations of pseudouridine (P less than 0.001), uric acid (P less than 0.001), and an unknown fluorescent solute, "UKF3" (P less than 0.01), differed in sera of HD and CAPD patients. When standardized with respect to serum creatinine concentrations, the concentration of the transfer-RNA catabolite, pseudouridine, was significantly (P less than 0.0001) higher in sera of CAPD patients than in HD patients, suggesting an increase in turnover of transfer RNA. In stepwise linear discriminant analysis, the combination of pseudouridine and the probably biochemically related fluorescent unknown, UKF3, contributed most to the differentiation between sera from CAPD and HD patients.

RNA metabolism in uremic patients: Accumulation of modified ribonucleosides in uremic serum

“…Pseudouridine (⌿), 1-methyladenosine (m 1 A), 1-methylinosine (m 1 I), 1-methylguanosine (m 1 G), N 4 -acetylcytidine (ac 4 C), N 2methylguanosine (m 2 G), adenosine (A), N 6 -methyladenosine (m 6 A), allopurinol ribonucleoside (APR), 3-methyluridine (m 3 U) and 5-bromouridine (br 5 U) were obtained from Sigma Chemical Co. (St. Louis, MO, USA). Uridine (U), guanosine (G) and cytidine (C) were obtained from Kohjin Co. (Tokyo, Japan), and xanthosine (X) from Nakarai Chemical Co. (Kyoto, Japan).…”

“…Pseudouridine derived predominantly from tRNA is not catabolized but excreted in urine as the intact molecule. The serum level of pseudouridine has been reported to be increased in uremic patients [3][4][5][6], especially when they are undergoing continuous ambulatory peritoneal dialysis (CAPD) [4]. Further analytical study on the metabolism of modified ribonucleosides in uremic patients is required to shed light on their possible roles as uremic toxins.…”

Are the classical markers sufficient to describe uremic solute accumulation in dialyzed patients? Hippurates reconsidered.

“…HPLC. This was performed as described previously (10,11). A column of "Ultrasphere Octyl" (C8-modifled silica), 4.6 mm (i.d.)…”

“…Twentytwo characteristic uremic solutes in sera of dialyzed and non-dialyzed uremic patients were subjected to principal component analysis, in order to explore interdependencies between these concentrations and their distribution in different patients. These ultraviolet-absorbing and (or) fluorescent solutes were analyzed by gradient-elution high-performance liquid chromatography (HPLC) as described previously (10,11).…”

Ultraviolet-absorbing organic anions in uremic serum separated by capillary zone electrophoresis, and quantification of hippuric acid

“…Organic acids in uremic serum can be analyzed, as a group, by use of temperature-programmed gas chromatography (17,18) or "high-performance" liquid chromatography (HPLC) with gradient-elution (9,(19)(20)(21), both of which are relatively time-consuming procedures. Specific analysis for HA has also been done colorimetrically (22) in the injected calibration solutions of 0, 12.5, 25, 50, and 125 p.moIJL for CZE analysis and 0, 25, 50, 100, and 250 p.moliL for HPLC analysis.…”