Vet Pathol Email Content Delivery
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Johnson, J. S.
Right arrow Articles by Baker, D. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Johnson, J. S.
Right arrow Articles by Baker, D. C.
Vet Pathol 43:726-732 (2006)
© 2006 American College of Veterinary Pathologists

Defective {gamma}-Glutamyl Carboxylase Activity and Bleeding in Rambouillet Sheep

J. S. Johnson, B. A. Soute, C. S. Olver and D. C. Baker

Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO (JSJ, CSO, DCB), Department of Biochemistry, University of Limburg, Maastricht, The Netherlands (BAS)

A flock of Rambouillet sheep was examined because of increased lamb mortality caused by ineffective hemostasis at parturition. Neonatal-affected lambs presented with inadequate hemostasis at the umbilicus, pale mucus membranes, and markedly prolonged activated clotting time. Affected lambs had consistently prolonged 1-stage prothrombin times and activated partial thromboplastin times that supported a defect in the common pathway or defects in both the intrinsic and extrinsic pathway of the coagulation cascade. Decreased activity of vitamin K-dependent procoagulant factors II, VII, IX, and X in male and female lambs suggested either a defect of the hepatic enzyme {gamma}-glutamyl carboxylase, or vitamin K1 2,3 epoxide reductase. Affected lamb hepatic {gamma}-glutamyl carboxylase activity was markedly decreased compared with that of age- and sex-matched control lambs, while vitamin K1 2,3 epoxide reductase and glucose-6-phosphatase activities were similar between an affected and normal lamb. Subcutaneous vitamin K1 supplementation did not increase vitamin K-dependent procoagulant factor activities in 3 lambs administered vitamin K1 daily. These data confirm defective {gamma}-glutamyl carboxylase activity as the cause of impaired coagulation of sheep in this flock. This flock represents the only viable animal model of hereditarily defective {gamma}-glutamyl carboxylase activity.

Key words: Gamma-glutamyl carboxylase; hemostasis; sheep; vitamin K.

Request reprints from Dr. Jeremy S Johnson, IDEXX Laboratories, 2825 KOVR Drive, West Sacramento, CA 95605 (USA). E-mail: jeremy-johnson{at}idexx.com






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2006 by the American College of Veterinary Pathologists.