Influence of age, sex, strain of rat and fat soluble vitamins on hemorrhagic syndromes in rats fed irradiated beef.

Abstract

It has been shown by a number of investigators working on this problem that the incidence of a hemorrhagic syndrome associated with the feeding of irradiated beef diets to the rat is influenced by the age, sex, and strain of rat employed. Administration of male hormones or castration of female rats results in an increased susceptibility to hypoprothrombinemia and hemorrhage; whereas the converse is true for the administration of estrogenic hormones or castration of the male animal. Changes in the composition of the diet, particularly the addition of large amounts of vitamins A and E, may increase mortality and depress prothrombin levels. Supplemental bile acids or an emulsifying agent have a beneficial effect, probably secondary to improved absorption of vitamin K. Irradiation of the beef in the diets which were studied is not a prerequisite for the development of low levels of prothrombin in the male rat. Hypoprothrombinemia may occur in animals fed similar diets containing nonirradiated beef and even in animals receiving a commercial stock laboratory chow. (auth)