| Autor: |
Alfin-Slater, Roslyn, Shimma, Yaichiro, Hansen, Herbert, Wells, Penelope, Aftergood, Lilla, Melnick, Daniel |
| Zdroj: |
Journal of the American Oil Chemists' Society (JAOCS); Jul1972, Vol. 49 Issue 7, p395-402, 8p |
| Abstrakt: |
The present study has involved biologically titrating linoleate vs. vitamin E using the male rat as the indicator. In the first of the titration studies, the dietary tocopherol level was held constant, while in the second study the linoleate intake was held constant. The investigation was conducted with male rats since these have a much higher linoleate requirement than females. By first depleting such animals of their stores of essential fatty acids by feeding a fat-free diet from weaning, a sensitive test organism was provided. These animals have an immediate need for linoleate during the repletion periods. If an imbalance between linoleate and vitamin E content existed in any of the dietary regimens, such an imbalance would have been more likely noted in test animals actively metabolizing the ingested linoleate. Based upon various nutritional and biochemical indices, the amount of tocopherol ordinarily included in the basic diets fed to our rats, 0.01% as dl-alphatocopheryl acetate, was adequate even when the diet provided up to 5% linoleate; an amount corresponding to ca. 12% of the total calories and providing a ratio of linoleate to the tocopherol of ca. 500:1. In the reverse biological titration with all test diets now providing the constant level of 5% linoleate, ratios of linoleate to vitamin E were satisfactory even in a ratio of as much as 2500:1 (or 0.4 mg gram of vitamin E per polyunsaturated fatty acid). The control animals continued on the fat-free diet indicated that there is a need for added tocopherols even in the absence of linoleate according to a number of biochemical indices. Based upon a number of accepted bioanalytical approaches, the minimum requirement for linoleate by the fat-depleted male rat was found to be between 100-200 mg/day or ca. 1-2% of the caloric intake. Although the fatty acid composition of tissue lipid fractions is markedly affected by the amount of linoleate in the diet, dietary tocopherol supplements have little effect on these values. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
Full text from SpringerLink