Fat, Ash and Calcium Contents of Rat Heart Tissue, Elasticity of the Aorta and Microscopical Vascular Changes in Rats of Different Ages

Abstract

In studying lipid and vitamin metabolism the fat, ash and Ca content of heart tissue were determined in rats, 5 and 15 months old. The elasticity of rat aortas was measured in the older group, and microscopical changes in the aorta walls were recorded in the younger group. The heart fat, ash and Ca content were not dependent on the diet given. Only the total fat content of the food might influenced the heart fat content. Female rats had higher ash contents in the heart tissue than their male littermates in both groups. The heart Ca content was higher in the older female rats but lower in the younger than in the corresponding male groups. In older animals the heart Ca content was definitely higher than in the younger groups; a similar but less important trend was seen in the ash content of the hearts. Heart fat content also increased but this could be due to the higher fat content of the older group''s diet. Aorta elasticity was stronger in females than in males of the older group. Histological changes in the aorta of the younger groups seemed somewhat more frequent and severe in the female than in the male animals. The lesions showed no early accumulation of lipoids, and could not be considered of atherosclerotic origin. No distinct relations of the incidence and severity of the lesions with plasma lipid levels could be demonstrated.