Harry J. Deuel

Studies of the distribution of vitamin A as ester and alcohol and of carotenoids in plasma proteins of several species

Abstract The distribution of vitamin A ester, alcohol, and lutein was studied in fractions of chicken plasma proteins obtained by ammonium sulfate fractionation or dialysis, 6–8 hr. after oral administration of vitamin A and lutein in an oily medium. The losses of vitamin A and carotenoids during fractionation were considerable in some cases, losses of vitamin A being as large as 50% at times. Although this made the interpretation of the distribution between precipitate and supernatant difficult, the following conclusions seem to be possible. Vitamin A ester was found to be associated with the least soluble, and vitamin A alcohol and lutein with the more soluble protein fractions. No mono- or diesters of lutein could be demonstrated in the plasma. In beef plasma, β-carotene and lutein and vitamin A alcohol were found in the more soluble protein fractions. In pig plasma, vitamin A alcohol was likewise associated with the more soluble protein. The hypothesis is put forward that specific plasma or lymph proteins may be responsible for the specificity of absorption of carotenoids and vitamin A.

Prolongation of Pseudopregnancy by Induction of Deciduomata in the Rat.

Summary The induction of deciduomata resulted in prolongation of pseudopregnancy to the period of normal pregnancy in the rat. This prolongation occurred in the absence of fetal tissue and was associated with the presence of metrial glands, maintenance of corpora lutea, and inhibition of follicular development.

Effect of hydrogenated triolein on utilization of essential fatty acids in the rat.

Summary Rats which were depleted of essential fatty acids after 16 weeks on a fat-free diet were maintained for 8 weeks thereafter on either a continued fat-free diet, fat-free diets containing 2 levels of hydrogenated triolein (containing 33% of trans isomers and no essential fatty acids), fat-free diets containing 2 levels of methyl linoleate, or fat-free diets supplemented with both linoleate and the hydrogenated triolein at the 2 levels. The animals receiving the linoleate supplement alone or the linoleate plus the hydrogenated triolein showed equivalent weight gains over an 8-week period. In the absence of the linoleate there was no aggravation of the deficiency syndrome. No observable antimetabolic activity of the hydrogenated triolein was evident.

Comparative Effects of Alpha-Tocopherol, DPPD and Other Antioxidants on Muscular Dystrophy in Guinea Pig.∗

Summary DPPD, Santoquin and DBH delayed but did not prevent the occurrence of muscular dystrophy in guinea pigs fed a highly purified diet deficient in vit. E. In contrast to these results, alpha-tocopherol acetate was fully protective in this regard.

Stereochemical configuration and provitamin A activity. X. A comparison of synthetic 15,15′-monocis-β-carotene (central monocis-β-carotene) with all-trans-β-carotene in the rat and chick

Abstract 15,15′-Monocis-β-carotene (central cis-β-carotene), prepared by Inhoffen et al. by total synthesis, was administered to depleted rats and chicks. When fed at a low daily level, it showed half the potency of all-trans-β-carotene. However, upon increasing the dosage, the provitamin A effect fell to one-third and less. Most of the synthetic carotene, when given to depleted hens in relatively large amounts, is mainly destroyed. Most of the recovered pigment was found in the droppings; a substantial fraction of it had undergone conversion into the all-trans compound.

A comparison of the ketolytic effect of succinic acid with glucose.

Korányi and Szent-Györgyi 1 have reported recently that succinic acid given as the calcium salt in daily amounts of 5 to 10 gm. or less is able to decrease the ketosis in diabetics. In the present investigations we have compared the ketolytic action of succinic acid with that of glucose when administered twice daily to fasting male rats weighing approximately 200 gm., in which the endogenous ketonuria was induced by the previous administration of a high butter-fat diet low in protein, as reported earlier. 2 The studies on ketonuria were made on the second to fifth fast days inclusive during which sodium chloride solution (fasting controls), sodium succinate in doses from 9.95 to 149.2 mg. per 100 gm. rat daily, or glucose in equivalent amounts (7.55 to 113.2 mg. per 100 gm. rat) was fed. Urine collections were made daily. The ketonuria of the fasting controls usually rises to a maximum on the third fast day, after which it diminishes rapidly. In Table I a summary of the data is given. No ketolytic effect obtained when as much as 149.2 mg. of succinic acid per 100 gm. rat was given although glucose at a comparable level gave a marked decrease in the acetonuria. This amount of succinic acid on a surface area basis is 50% greater than the largest dose employed by Korányi and Szent-Györgyi. As slight decrease in ketonuria appears when only 7.55 mg. of glucose is given while a dose of 37.8 mg. caused an average decrease of acetone-bodies in the urine from 33.7 mg. per 100 gm. rat in the control tests to 19.4 mg. There was no evidence of diarrhea in any experiments nor of other toxic effects ascribable to the succinic acid.

The basal metabolism in vitamin B deficiency.

The heat production in dogs during rest has been determined with the respiration calorimeter when these animals were fed with diets deficient in vitamin B. The purified food mixture fed to Dogs XXIV and XXV was complete in all respects with the exception of vitamins B and C. It was composed of casein, butter fat, lard, sucrose, salt mixture, and bone ash. Vitamin C was omitted since it has been shown that dogs, when fed with such mixtures containing vitamin B, remain in normal condition over long periods of time and show no effects from this lack. 1 Basal metabolism measurements were made by the usual technique employed in this laboratory. On Dog XXIV the metabolism was determined at approximately weekly intervals during the course of the ingestion of the standard vitamin B-free diet. In this animal the basal heat production gradually fell, but the diminution was no greater than that which would be expected from the decreased body weight of the animal due to a decreasing food intake. On the day before the development of polyneuritic symptoms and on the four days following the removal of these symptoms by the administration of 20 gm. of yeast vitamin (Harris), the basal metabolism was remarkably constant, thus indicating that vitamin B deficiency per se does not influence heat production. In the case of Dog XXV the basal metabolism was determined at the height of polyneuritis and was found to be about 25 per cent higher than the normal value to which it gradually fell after the removal of the symptoms. In this case the high heat production must have been due to the extreme muscular tonicity caused by the polyneuritic condition and only indirectly to the vitamin B deficiency.

A method for the biological preparation of deuterium-labeled cholesterol from the hen's egg.

Summary A simple, relatively inexpensive method for the biological preparation of deuterium-labeled cholesterol from hens eggs has been described. The daily incorporation and subsequent disappearance of the deuterium into the cholesterol has been followed.

Thiouracil and conversion of carotene to vitamin A measured by liver storage in the rat.

In a recent report, Canadell and Valdecasas 1 fed rats, which previously were on a vitamin A-free diet with thiouracil administered in the drinking water, 60 γ of carotene per week. The administered carotene was unable to relieve the ocular symptoms produced by a vitamin A deficiency. However, these symptoms were alleviated if small amounts of thyroid powder were administered with the carotene or vitamin A was fed to the thiouracil-treated animals. Their interpretation of this phenomenon was that it involved an inhibition of carotenase. If this is true, then the feeding of carotene to vitamin A deficient-animals previously treated with thiouracil should produce little or no vitamin A in the liver. Therefore, this experiment was attempted, and a preliminary report of the results obtained is presented. Twenty-six rats were placed on a vitamin A-low diet when they were 10 days old. When they reached a body weight of 43 g, they were divided into 2 groups. One group was continued on the same diet for 4 weeks while the second group received a similar diet to which 0.25% of thiouracil had been added. All rats were continued for an additional 2 weeks on identical diets except that they were made vitamin A-free by replacing the commercial casein with vitamin A-free test casein (General Biochemicals, Inc.). Some of the animals in each group received a single oral dose of a solution of β-carotene in cottonseed oil containing 348 ρ while the remaining rats, which served as controls, received cottonseed oil. The animals were sacrificed at 36 hours, 5 days or 7 days. Since the vitamin A levels in the different groups did not show any significant trend with time, the results obtained with animals sacrificed at 36 hours, 5 or 7 days have been averaged together.

Provitamin A activity of a structural isomer of cryptoxanthin and its methyl ether.

Abstract Synthetic isocryptoxanthin (4-hydroxy-β-carotene) and its methyl ether show provitamin A effects in the rat which are practically identical with those produced by naturally occurring cryptoxanthin (3-hydroxyβ-carotene), and hence corresponding to one-half of the β-carotene effect.