Effects of Dietary Selenium, Methionine, Fat Level and Tocopherol on Rat Growth

Publisher Website
Google Scholar
Abstract
It is possible to relate the tocopherol requirement of the rat to the dietary or tissue lipid fatty acids by means of growth curves when the methionine levels and other components of the diet are controlled and the environment is optimal. One of the dependent variables is the amount of selenium available to the animal. Conversely, if the α-tocopherol content of the diet is controlled at a low level, the growth curves can be related to the levels of biologically available selenium. Such growth curves show that the selenium requirement of the tocopherol-deficient rat has a very narrow optimal range and that the toxicity of selenium may be decreased by adding methionine. The selenium content of casein is variable and, to only a moderate degree, biologically available. When rats were fed low levels of dietary fat (1 to 7.5%) in a diet essentially devoid of tocopherol, the time required for the production of creatinuria, a sign of nutritional muscular dystrophy, was inversely proportional to the dietary fat level. The tocopherol requirement also decreased markedly as the dietary fat level was lowered. The time in weeks required to produce creatinuria was correlated with the fatty acid composition of the muscle phospholipid and neutral lipids.