Abnormal prothrombin in the vitamin K-deficient rat

Area of Science:

• Biochemistry
• Hematology
• Pharmacology

Background:

• Vitamin K is essential for synthesizing functional blood clotting factors.
• Vitamin K deficiency causes undercarboxylated clotting factors, impacting coagulation.
• The response of rat prothrombin to vitamin K interference was previously unclear.

Purpose of the Study:

• To quantify undercarboxylated prothrombin in vitamin K-deficient rats.
• To clarify the extent of vitamin K's role in rat prothrombin carboxylation.

Main Methods:

• Development of specific amidolytic and immunochemical assays for rat prothrombin.
• Analysis of plasma from vitamin K-deficient and Warfarin-treated rats.

Main Results:

• Vitamin K-deficient and Warfarin-treated rats exhibit undercarboxylated rat prothrombin.
• This abnormal prothrombin is non-BaSO4 adsorbable.
• The concentration of undercarboxylated prothrombin is 5-10% of normal plasma levels.

Conclusions:

• Vitamin K deficiency demonstrably affects rat prothrombin carboxylation.
• The developed assays provide a reliable method for assessing vitamin K status in rats.
• Findings resolve controversy regarding vitamin K-dependent clotting factor synthesis in rats.