Decreased Renal Vitamin K-dependent Gamma-glutamyl Carboxylase Activity in Calcium Oxalate Calculi Patients

Objective: To study the activity of vitamin K-dependent gamma-glutamyl carboxylase in patients with calcium oxalate (CaOx) urolithiasis compared with healthy individuals and to assess its relationship to the renal calcium oxalate urolithiasis.

Methods: Renal parenchymas were harvested from urolithic patients and renal tumor patients undergoing nephrectomy. The renal carboxylase activity was evaluated as the radioactivity of [(14)C] labeled sodium bicarbonate in carboxylic reactions in vitro using beta-liquid scintillation counting.

Results: Significantly reduced activity of renal vitamin K-dependent gamma-glutamyl carboxylase was observed in the urolithic group as compared with normal controls (P < 0.01).

Conclusion: It suggests that the reduced carboxylase activity observed in the urolithic patients may play an important role in the course of renal calcium oxalate urolithiasis.