Philip L. Harris

Note on the linoleic acid-tocopherol relationship in fats and oils

ConclusionsThe linoleic acid and total tocopherol content of animal and vegetable oils, for which these characteristics are known, are correlated with a high degree of significance;r=+0.79.

Blood Tocopherol Values in Normal Human Adults and Incidence of Vitamin E Deficiency

Summary The mean tocopherol concentration in 197 factory workers in Rochester, N. Y., was 1.05 ± 0.32 mg/100 ml. About 7% of the subjects had less than 0.50 mg tocopherol/100 ml, the level below which red blood cell hemolysis tests become positive, indicating Vit. E deficiency.

Effect of DPPD, Methylene Blue, BHT, and Hydroquinone on Reproductive Process in the Rat.∗:

Summary and conclusions 1) Vit. E. bio-assays (prevention of resorption-gestation) of both methylene blue and DPPD indicated a low order of activity. However, this apparent tocopherol-like potency was due probably to a protective or sparing effect on small residual quantities of vit. E in the diet and in the body tissues. Under conditions where the diet was rigorously freed of tocopherol and the depletion period was extended, methylene blue and DPPD were found by other investigators to be completely devoid of vit. E activity. 2) At higher levels of supplementation, both methylene blue and DPPD were toxic. Methylene blue in doses of 100 mg/ day killed pregnant female rats. Feeding pregnant rats diets containing DPPD at a level of 0.0125% in the diet resulted in mortality of their young. Higher levels of DPPD induced prolonged gestation and maternal mortality. Neither BHT (0.313%) nor hy-droquinone (0.3%) produced these symptoms of toxicity, but BHT at the 1.55% level in the diet resulted in drastic loss of weight and fetal deaths.

Bioassay of Vitamin A Compounds

Publisher Summary In the current stage of evolution of vitamin A bioassays, it is realized that two types are needed: One type to measure the potential or total vitamin A activity per molecule is needed to study and evaluate such items as vitamin A isomers, provitamins A, metabolites, and synthetic compounds related to vitamin A. Eventually results from this type may lead to complete understanding of the relationship between chemical structure and biological activity. The other type of bioassay to measure the over-all benefit of the vitamin A preparation administered is needed to evaluate the practical vitamin A potency of pharmaceuticals, foods, and feeds. It is conducted under simulated practical feeding conditions, and the potential availability of the vitamin A present is affected by such factors as losses due to mixing, processing, and storing. The results of such an assay, in which potency and factors affecting potency are confounded, represent practical availability. This chapter briefly discusses the various bioassay methods available and illustrates some of them with examples from the literature. Those aspects of technique and interpretation that make the bioassays either a measure of total vitamin A or a measure of availability are emphasized.

Molecularly distilled monoglycerides. III. Nutritional studies on monoglycerides derived from cottonseed oil

Summary and ConclusionsMonoglycerides, prepared from cottonseed oil, were fed to three generations of rats at a 15% and a 25% level as the sole source of fat in the diet. Refined cottonseed oil was fed to comparable groups of rats at the same levels.No significant differences were found between the monoglycerides and the cottonseed oil in their nutritive value as measured by growth response, reproduction ability, and lactation performance. Absorption of fatty acids, either as monoglycerides or as the original oil, from the intestinal tract was the same as shown by essentially equal coefficients of absorption for the two types of lipid at a 25% level in the diet.

Lipogranuloma from dietary saturated fats: Production and reversal

Abstract Lipogranuloma, a foreign-body-type reaction in adipose tissue, was observed in rats fed diets containing 35–50% levels of saturated fatty acids fed as palmitic acid, stearic acid, ethyl stearate, hydrogenated lard, or monoglycerides or acetylated monoglycerides made from hydrogenated lard. The incidence and severity of the reaction were approximately parallel to the amount of saturated fatty acid absorbed. Control groups fed lard or triacetin did not develop lipogranuloma during the 48-week test period. Replacing the diets containing saturated fat with one containing 20% corn oil led to prompt diminution (evident in all groups after 8 weeks) and eventual disappearance (essentially absent from all groups after 24 weeks) of the lipogranuloma. After reversal of the reaction, the adipose tissue showed no signs of damage.

Determination of 9-cis isomers of vitamin A by reaction with opsin☆☆☆

Abstract A procedure is described for the determination of the 9-cis components in pure or concentrated mixtures of vitamin A isomers. The method includes: saponification of esters; low temperature desterolization; purification of retinols on alumina; oxidation of retinols with MnO2; and specific reaction of 9-cis-retinals with opsin, a protein from the retina, to form isorhodopsin (λmax = 487 mμ). As little as 0.25 μg of 9-cis isomers can be determined, with an average recovery of 96 ± 7% S.D. Application of the procedure to liver oils from fish, cattle, sheep, pigs, and rats showed 9-cis isomer contents ranging from 1 to 30% of total vitamin A.

The lipide-bound volatile acids of animal fats.

Abstract Volatile acids have been recovered from saponified fats by steamdistillation. Identification of the acids was accomplished by paper chromatography of their hydroxamate derivatives. Analyses of various tissue fats from the rat, dog, and guinea pig, and of human blood lipides showed small amounts of lipide-bound volatile acids in every fat tested. Feeding distilled, acetylated monoglycerides to rats at dietary levels up to 50% increased the lipide-bound, steam-distillable acids in blood but not in tissue fats or carcass fat. The low levels of these acids which were found in tissue fats from a dog fed a standard dog meal were not elevated by feeding a diet containing 25% distilled, acetylated monoglycerides.

Biochemical studies on vitamin A. X. A nutritional investigation of synthetic vitamin A in margarine

SummaryThe growth, reproduction, and lactation of three generations of albino rats fed diets containing 7.5% of margarine oil fortified with synthetic vitamin A palmitate to contain 1,850,000 units of vitamin A per pound of fat (1,500,000 units per pound of margarine) was investigated. This level of supplementation gave normal responses comparable to those shown by animals fed regular margarine oil (18,500 units of natural vitamin A per pound of fat or 15,000 units per pound of margarine).

Relation of vitamin E to acute physiological stress.

Summary and Conclusions The nutritional status of rats with respect to vit. E had no effect on the adrenal cortical activity (as measured by change in adrenal ascorbic acid concentration) following acute physiological stress (epinephrine injection or exposure to cold). Neither the content of vit. E in the adrenal glands of normal adult rats nor the blood tocopherol content of tocopherol-supplemented or tocopherol-deficient rats was changed following physiological stress. Thus, vit. E is apparently not a factor in the anterior pituitary-adrenal cortical response to acute physiological stress, although vit. E may be related to the manner in which the tissues utilize the adrenal cortical hormones released as a result of such stress.