Abstract |
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 K(1) 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 K(1) 2,3 epoxide reductase and glucose-6-phosphatase activities were similar between an affected and normal lamb. Subcutaneous vitamin K(1) supplementation did not increase vitamin K-dependent procoagulant factor activities in 3 lambs administered vitamin K(1) 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.
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Authors | J S Johnson, B A Soute, C S Olver, D C Baker |
Journal | Veterinary pathology
(Vet Pathol)
Vol. 43
Issue 5
Pg. 726-32
(Sep 2006)
ISSN: 0300-9858 [Print] United States |
PMID | 16966451
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Blood Coagulation Factors
- Carbon-Carbon Ligases
- glutamyl carboxylase
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Topics |
- Animals
- Animals, Newborn
- Blood Coagulation Disorders, Inherited
(enzymology, veterinary)
- Blood Coagulation Factors
(metabolism)
- Carbon-Carbon Ligases
(metabolism)
- Female
- Hemostasis
- Male
- Microsomes, Liver
(enzymology)
- Sheep
(classification)
- Sheep Diseases
(enzymology)
- Time Factors
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