1999 Fiscal Year Final Research Report Summary
Autoanalysis of Urinary Stone-rlated Facors and Urinary Saturation Lebeles of Stone Compositions
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants |
|Research Institution||Wakayama Medical College |
HIRANO Atsuyuki Wakayama Medical College, Urology, Assistant Professor, 医学部, 講師 (30218797)
INAGAKI Takeshi Wakayama Medical College, Urology, Associate, 医学部, 助手 (30254543)
TOUGE Hirishi Wakayama Medical College, Urology, Associate, 医学部, 助手 (20305759)
MORITA Teruo Wakayama Medical College, Urology, Associate (50291612)
OGURA Hideaki Wakayama Medical College, Urology, Associate (60264496)
MORIMOTO Shigeyoshi Wakayama Medical College, Urology, Assistant Professor (20094683)
OHKAWA Tadashi Wakayama Medical College, Urology, Professor (90073733)
|Project Period (FY)
1997 – 1999
|Keywords||renal calculus / capillary electrophoresis / urinary oxalate / urinary citrate / plasma oxalate / renal oxalate clearance / urinary cations|
Urinary oxalate and citrate are the important promoter and inhibitor for urinary stone formation. Simultaneous dermination of both anions was established by capillary electrophoresis (CE) in this study. A Waters Quanta 4000E was used. Data was acquired on a microcomputer with Millennium soft ware from Waters. The electrolyte solution contained 25mM de-sodium hydrogen phosphate and 0.5mM anion BT. The coefficient variation and the recovery were excellent. The measurements of both anions by CE agreed with the values of oxalate by inochromatography and citrate by enzymatic procedure.
Oxalate metabolism has been noted to play an important role on urinary stone formation. We tried, therefore, the determination of plasma oxalate using CE. The determination of plasma oxalate needs a high sensitivity because of its extremely low concentration, and to minimize oxalogenesis in vitro from ascorbic acid and glyoxylate. In our method, a larger caliber of capillary, a longer injection time of sample
and a lower hold of sample dilution were adopted than in urinary oxalate determination. To minimize oxalogenesis, blood samples were ultrafiltrated under the lower temperature, then ultrafiltrates were rapidly acidified with a solution of 300mM boric acid and 50mM phosphoric acid (pH 2.0). The minimum detectable limit of plasma oxalate was 0.9μM, the coefficient variation was 5.8-16.0% and the recovery rate was 102% (88-126%). The plasma oxalate levels in 8 adults males were 2.39±1.46μM (Mean±SD), which agreed with the values in the recent repots.
As a practical application of plasma oxalate determination, we measured renal oxalate clearance (Cox). Cox with one hour method were 72.9±20.0 ml/min in 6 healthy controls, and 83.2±27.8 ml/min in 8 stone formers. Oxalate/creatinine clearance (Cox/Ccr) ratios in each group were 0.70±0.16 and 1.11±0.34 respectively. Cox with 24 hours method were significantly higher than with one hour method, possibly because of an influence of dietary oxalate. Therefore, one hour method is advisable for Cox measurements. Which the Cox/Ccr ratios were higher than 1.0, suggests that oxalate would be excreted from the renal tubules.
Although the determination of urinary anions by CE had been already established, we tried to measure NH4ィイD1+ィエD1, KィイD1+ィエD1, CaィイD1++ィエD1, NaィイD1+ィエD1, MgィイD1++ィエD1 in urine by this method. Differed from the oxalate and citrate determination, the system was used with a negative supply. The electrolyte solution contained 2mM crown ether/18-crown-6, 65mM HIBA and 5mM UV Cat-1. Separations of each cation peak in 1000 holds diluted urine samples with distilled water were satisfactory. Recoveries of each added 50μM cation were 90.0%, 88.1%, 75.6%, 102.0% and 100.8%. Less
Research Products (1 results)