Role of plasma protein and low-molecular weight substances in the change of hydroxyl radical scavenging activity in hemodialysis patients.

While it is well known that hemodialysis (HD) patients with end stage renal failure are exposed to high oxidative stress, there is not a general opinion regarding whether antioxidant activity is high or low in these patients. We evaluated the variation of plasma hydroxyl radical scavenging activity (p-HRSA) by a single-session of HD in 69 patients by using a new system, reactive flow-injection electron spin resonance. And then comparing p-HRSA with their biochemical parameters, we tried to elucidate what components affected p-HRSA in the HD patients. The average of p-HRSA significantly increased after HD and the variation of p-HRSA by HD was correlated with that of plasma total protein (TP). In 5 patients however, their p-HRSA decreased after HD, in spite of increasing TP. In pre-HD, the p-HRSA values and hydroxyl radical scavenging activity of low-molecular weight fraction of plasma were significantly higher in these 5 patients than in patients whose p-HRSA increased after HD. These 5 patients were in an inflammatory state. These findings suggest that p-HRSA is mainly affected by TP, but caution should be exercised in patients who have high p-HRSA before HD and whose p-HRSA does not increase after HD.

Comparison of hydroxyl radical generation in patients undergoing coronary artery bypass grafting with and without cardiopulmonary bypass.

We measured the hydroxyl radical (.OH) generation in fourteen patients undergoing coronary artery bypass grafting (CABG), of whom seven patients underwent on-pump CABG with cardiopulmonary bypass (CPB) and seven patients underwent off-pump CABG without CPB. To detect .OH generation, we measured the urinary excretion of .OH products of creatinine (Cr), creatol (CTL; 5-hydroxycreatinine) and methylguanidine (MG) with HPLC using the one point sampling and collected urine during and after the operation. The urinary CTL value corrected urinary Cr value of on-pump CABG significantly increased about 3-5 times from the beginning of CPB to 4 h after operation compared to the baseline value before CPB in both the collected urine and the one point sampling urine. The urinary MG/Cr value in both groups did not change significantly. Significantly increased .OH generation was found during and soon after on-pump CABG.

[Novel renal function marker, ATP--establishing the normal range, cases of anti-tumor drags administration for urinary-track tumor, diabetic diseases and a newborn baby].

Urinary free ATP assay by the firefly luciferin-luciferase method is a rapid and simple method for determining renal function, especially uriniferous tubule function. Normal range of urinary free ATP concentration, daily ATP excretion in urine, urinary ATP/creatinine value and ATP decomposition activity in urine is 1.1 x 10(-9)-3.4 x 10(-8) M, 4.0 x 10(-9)-4.1 x 10(-8) mole, 5.0 x 10(-13)-5.9 x 10(-11) mol/mgCr and 100-77% express for the remaining rate of additional ATP, respectively. A significant correlation was found between free ATP concentration and daily ATP excretion in urine with a correlation coefficient of 0.84. In cases of anti-tumor drug(cisplatin = cis-diamminedichloroplatinum II) administration for urinary-track tumor, abnormal urinary free ATP concentration and ATP decomposition activity in urine were clearly demonstrated after a few days of cisplatin administration. The appearance of a tendency toward abnormal relative ATP values were similar to changes in beta 2-MG and NAG values. Diabetic patients often demonstrate unusually high values of urinary free ATP concentration. In asphyxia of the newborn, urinary ATP/creatinine value were significantly higher than those in healthy newborn, but urinary NAG values did not differ.