The Protective Effect of Dietary Fat on Immature Rats Fed Thyroid

Abstract

Crystalline vitamin B₁₂ has no appreciable effect in counter-acting the growth-retarding action in rats of desiccated thyroid powder in a fat-free, sucrose-casein diet. Methyl linoleate and cottonseed oil administration protect the immature rat against growth retardation when the rat is fed a fat-free, sucrose-casein diet to which thyroid (0.05% of the diet) has been added. The levels of essential fatty acid (50 mg of linoleate per day) and cottonseed oil (500 mg per day) which were fed to hyperthyroid rats do not protect the animal against enlargement of the heart and protect it only partially against enlargement of the kidney. The possible relationship between the protective activity of fat and that of liver for immature rats fed thyroid is discussed.