menatetrenone and Thrombosis

Vitamin K is involved in the biosynthesis of a number of blood coagulation factors and bone proteins. It has been suggested that the vitamin K requirement of bone tissue is higher than that of the liver. Here we report that in rats very high doses of vitamin K affected neither the blood coagulation characteristics nor the blood platelet aggregation rate. This was observed for both phylloquinone and menaquinone-4. Both vitamers were also tested for their effects on the arterial thrombosis tendency in the rat aorta loop model. The mean obstruction times were prolonged at a high intake of menaquinone-4 (250 mg/kg body weight/day), and shortened after a similarly high phylloquinone regimen. Since (a) both vitamers only differ in their aliphatic side chains; and (b) a similar trend was observed after administration of phytol and geranylgeraniol, we conclude that the modulation of the arterial thrombosis tendency is accomplished by the side chain of vitamin K.

Topics: Animals; Blood Coagulation; Diet; Dietary Fats, Unsaturated; Disease Models, Animal; Disease Susceptibility; Diterpenes; Dose-Response Relationship, Drug; Male; Phytol; Platelet Aggregation; Rats; Rats, Wistar; Thrombosis; Vitamin K; Vitamin K 1; Vitamin K 2; Vitamin K Deficiency