Effects of urinary prothrombin fragment 1 in the formation of calcium oxalate calculus.
OBJECTIVE
We investigated the effects of urinary prothrombin fragment 1 in the formation of calcium oxalate urolithiasis.


METHODS
Fresh urine and renal parenchyma from patients with calcium oxalate calculus and normal controls were collected. Urinary prothrombin fragment 1 was isolated and purified from urine. It was identified by sodium dodecyl sulfide-polyacrylamide gel electrophoresis and analysis of its first 13 N-amino acids. The inhibitory activity of urinary prothrombin fragment 1 on calcium oxalate crystal growth was tested by the seeded crystallization technique. Meanwhile, the gamma-carboxyglutamic acid composition of urinary prothrombin fragment 1 was analyzed by a previously described method and genetic mutation of the gamma-carboxyglutamic acid domain of urinary prothrombin fragment 1 from renal parenchyma was detected by polymerase chain reaction-single strand conformational polymorphism sequencing.


RESULTS
The gamma-carboxyglutamic acid composition of urinary prothrombin fragment 1 was significantly decreased from normal (24.4 to 1.7 mol/1,000 amino acids) in patients with calcium oxalate calculus. The mean growth index +/- SD of urinary prothrombin fragment 1 to calcium oxalate crystals was 42.3 +/- 4.2 compared with the normal index of 19.2 +/- 2.8 (p <0.01). The polymerase chain reaction-single strand conformational polymorphism sequencing technique revealed no genetic mutation of the gamma-carboxyglutamic acid domain of urinary prothrombin fragment 1 in patients with calcium oxalate calculus.


CONCLUSIONS
The gamma-carboxyglutamic acid composition of urinary prothrombin fragment 1 as well as its ability to inhibit calcium oxalate crystal growth was significantly decreased in patients with calcium oxalate calculus. This was not caused by genetic mutation of the gamma-carboxyglutamic acid domain of urinary prothrombin fragment 1. It is important to elucidate the mechanisms of calcium oxalate stones in view of urinary prothrombin fragment 1.
Liu
Jihong
J
Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan Hubei 430030, People's Republic of China. Jhliu888@hotmail.com
Chen
Junhui
J
Wang
Tao
T
Wang
Shaogang
S
Ye
Zhangqun
Z
D015055:1-Carboxyglutamic Acid / Q000737:chemistry; D000328:Adult; D000596:Amino Acids / Q000032:analysis; D002129:Calcium Oxalate; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008875:Middle Aged; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000652:urine*; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000652:urine*; D011516:Prothrombin / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000652:urine*; D014545:Urinary Calculi / Q000503:physiopathology* / Q000652:urine
D000596:Amino Acids; D010446:Peptide Fragments; D011498:Protein Precursors; D002129:Calcium Oxalate; D015055:1-Carboxyglutamic Acid; C029733:prothrombin fragment 1; D011516:Prothrombin