Lipid Pattern in Experimental Canine Atherosclerosis.

• The first experimental evidence that cholesterol is an atherogenic factor was presented by Anitschkovv and Chalatow. Rittenberg and Schoenheimer's demonstration that animals can synthesize cholesterol, and other investigationswhich show that dietary fat can effectively influence serum cholesterol levels in man, focused attention on dietary lipids other than cholesterol in atherogenesis. Experimental hypercholesterolemia and atherosclerosis have been produced in rabbits by feeding a cholesterol-free diet containing a high level of saturated fat; *• ° isocaloric substitution of fats containing linoleic acid does not produce hypercholesterolemia or atherosclerosis. Holman 1U and Holman and Peifer have demonstrated that both dietary cholesterol and saturated fat increase the dietary requirement for essential fatty acids or somehow impair their utilization. It is possible, therefore, that in experimental animals dietary cholesterol and saturated fat induce lesions of atherosclerosis by producing a deficiency of essential fatty acids. Such a mecha-