Studies on the Hemorrhagic Sweet Clover Disease

Abstract

The ingestion of 3,3′-methylenebis (4-hydroxycoumarin) induced a hypoprothrombinemia in rats. A single dose of 2.5 mg. to an adult rat lowered the prothrombin activity to 22% of normal in 24 hours, when maximum lowering was observed. The maximum effectiveness of the anticoagulant was observed on rations low in vitamin K. Factors which counteracted the anticoagulant were present in a grain ration, in fish meal and in alfalfa. The factor in alfalfa could be extracted with petroleum ether. Vitamin K counteracted the hypoprothrombinemia induced by the anticoagulant, whether given before the anticoagulant, with it, or 12 hours later. All forms of the vitamin studied were active: 2-methyl 1,4-naphthoquinone, 2-methyl 1,4-naphthohydroquinone diacetate, vitamin K₁ and the water-soluble 2-methyl 1,4-naphthohydroquinone 3 sodium sulfonate. The continued administration of the anticoagulant resulted in severe spontaneous hemorrhages which caused the death of the animals. Their survival times could be prolonged by the ingestion of vitamin K but not by such dietary supplements as choline, ascorbic acid, wheat germ oil, hydrogenated fat, or condensed milk.