The lipotropic factors choline and inositol fail to exert a prophylactic effect against hypercholesterolemia, organ lipidosis and atherogenesis in the cholesterol-fed chick.
Restriction of dietary intake even to the point of emaciation gave no protection against atheromatosis or hypercholesteremia in chicks on a diet supplemented with cholesterol. These results show that there is no necessary relationship between the amount of body fat and atherosclerosis.
The development of atherosclerosis in very young chicks challenges the concept that atherogenesis depends upon senescence. Instead, the age period, rather than age, seems to be the more significant factor in atherogenesis. This is so since the regulation of the plasma cholesterol level is shown to vary at different age periods. During the first two months of life of the chick, a resistance to hypercholesteremia and atheromatosis is seen. At the eighth week, corresponding to the time of puberty, the plasma cholesterol rises markedly, despite an unchanged dietary regimen. The resistance to vascular lesions disappears and atheromatosis develops rapidly over the next few weeks. This indicates that endogenous mechanisms dependent upon the age period are important factors in the tendency to hypercholesteremia and atherogenesis.
Feeding chicks a mash enriched with 0.25 per cent cholesterol plus 5 per cent cottonseed oil induces a minimal sustained hypercholesterolemia. After 35 weeks of this regimen, birds exhibited a high incidence of gross cholesterol-induced atherosclerosis, particularly prominent in the thoracic aorta. The presence of atherosclerosis in these chicks with minimal diet-induced hypercholesterolemia lends further experimental support to the concept of the relationship of cholesterol in general, and exogenous cholesterol in particular, to the pathogenesis of human atherosclerosis.
Repeated implantations of diethylstilbestrol pellets cause a sustained hyperlipemia in the chick, and atherosclerosis eventually supervenes. Desiccated thyroid significantly reduces the incidence and degree of the stilbestrol-induced atherosclerosis in the chick, although it is without sustained effect upon the plasma and tissue lipids. T
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.