The effect of cortisone on the serum lipids and on the development of experimental cholesterol atherosclerosis in the rabbit.

An experiment was performed to determine the effect of cortisone on the serum lipids and on the development of experimental cholesterol atherosclerosis in the rabbit. Litter mate rabbits of the same sex were employed; both sexes were represented in the experiment. The report is based upon four experimental groups comprising (1) 12 rabbits fed cholesterol and treated with cortisone vehicle; (2) 12 rabbits fed cholesterol and treated daily with cortisone; (3) 11 rabbits treated with cortisone; and (4) 7 rabbits that received cortisone vehicle. It was observed that: (1) There was less aortic atherosclerosis in the cholesterol-fed cortisone-treated rabbits as judged by both morphological and chemical means than in the rabbits fed cholesterol without cortisone treatment. (2) Cortisone depressed appreciably the hypercholesterolemia resulting from the feeding of cholesterol to rabbits. (3) Cortisone treatment caused a moderate hypercholesterolemia in normal rabbits. (4) Cortisone caused a moderate increase in serum lipid phosphorus equal to that produced by cholesterol feeding alone. (5) The combination of cholesterol feeding and cortisone did not result in a higher phospholipidemia than either one of these agents alone. (6) Cortisone caused a great increase in serum-neutral fat; it was not apparent whether cholesterol feeding affected the neutral fat lipemia due to cortisone treatment alone. (7) The total cholesterol to lipid phosphorus ratio was about normal in the rabbits that received cortisone only. It was doubled in the animals receiving both cholesterol and cortisone, and it was increased about four times in those that received only cholesterol. The significance of the alterations in the serum lipids induced by cortisone is discussed in relation to the inhibition of the development of aortic atherosclerosis that occurred in the cholesterol-fed rabbits treated with cortisone.