Evidence that free gamma carboxyglutamic acid circulates in serum.
We report a rapid, sensitive and reproducible method to measure free gamma-carboxyglutamic acid (GLA) in serum using precolumn derivatization with O-phthalaldehyde, reversed-phase chromatography and deproteinization of serum by ultrafiltration. Serum free GLA level in 62 healthy adults was 167 +/- 46 pmol/ml and was increased (302 +/- 195 pmol/ml) in 14 patients with primary hyper-parathyroidism, a disease characterized by an increased bone turnover. Peptide bound GLA averaged 413 pmol/ml. In rabbits receiving massive doses of warfarin during 6 days there was a time- and dose-dependent decrease of serum free GLA but a significant fraction was still measurable. These data indicate that free GLA circulates and originates both from the metabolism of the vitamin K-dependent clotting factors and from bone metabolism.
INSERM Unit 234, Hôpital Edouard Herriot, Lyon, France.
B
B
Fournier
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E
Gineyts
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PD
Delmas
D015055:1-Carboxyglutamic Acid / Q000097:blood*; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood; D008297:Male; D008722:Methods; D010455:Peptides / Q000378:metabolism; D011485:Protein Binding; D011817:Rabbits; D014812:Vitamin K / Q000378:metabolism; D014859:Warfarin / Q000494:pharmacology
D010455:Peptides; D014812:Vitamin K; D015055:1-Carboxyglutamic Acid; D014859:Warfarin