Ascorbic Acid Requirement Research Articles

Attachment and short-term maintenance of motility and viability of Entamoeba histolytica in a defined medium.

Organic requirements for attachment to glass, elongation, and motility of Entamoeba histolytica, have been determined. The trophozoite, which has been grown axenically only in highly complex media with reduced oxygen tensions, remains rounded and detached when placed in a Tris-HCl buffered solution containing NaCl, KCl, MgClI, and CaCl2. A maintenance medium in which the amebae could attach to glass, elongate, and remain motile and viable for 12 to 24 h was devised with the addition of cysteine, ascorbic acid, bovine serum albumin, and the vitamin solution of medium NCTC No. 107. Tris-HCl was the most effective buffer tested and the optimal pH was 6.9 to 7.0. Survival, but attachment, of the amebae was decreased at osmolalities ranging between 110 and 180 milliosmoles/kg, whereas both functions were decreased above approximately 260 milliosmoles/kg. Bovine serum albumin, the most effective of the proteins tested, and the vitamin solution helped maintain attachment of some ameba strains, but were not required by other strains. The requirements for cysteine and ascorbic acid were absolute and highly specific. During incubation in the maintenance medium, cell volumes decreased. Sensitivity of the organisms to agglutination by concanavalin A, wheat germ agglutinin, soybean agglutinin and fucose binding protein remained unchanged.

Nutritional requirement of ascorbic acid by Indian major carp, Cirrhina mrigala, during early growth

Using synthetic diets, hatchlings of Cirrhina mrigala (obtained through induced breeding) were fed graded levels of ascorbic acid: 0, 60, 300, 600, 900, and 1200 mg/kg diet for 240 days. Studies on survival, growth and morphological changes of these fishes are reported. Statistical analysis of growth, deformity and survival rates at these levels suggested an optimum requirement of 650–750 mg ascorbic acid/kg diet in this early part of the life of the fish. Avitaminosis resulted in poor growth, high mortality rate (up to 42%), severe haemorrhages, fin necrosis, increased pigmentation and spinal flexures. 60 mg and 300 mg ascorbic acid/kg dietary levels also resulted in poor survival and growth rates. Skeletal deformities were also observed in some of these fish.

Studies on Ascorbic Acid Related to the Genetic Basis of Scurvy

This chapter presents the studies on ascorbic acid related to the genetic basis of scurvy. The importance of ascorbic acid has long been known, scurvy being the first recognized deficiency disease in humans. The vitamin has been shown to be involved in biological hydroxylation reactions of a number of metabolic pathways. Studies with radioactive tracers have shown that ascorbic acid is derived from glucose as a part of the glucuronic acid pathway. It is found that in the presence of hydroxylamine or semicarbazide L-gulonolactone oxidase, which had been purified nearly to homogeneity, converted D-glucuronolactone to ascorbic acid. The final step in the pathway from glucose to ascorbic acid is catalyzed by L-gulonolactone oxidase. The requirement for ascorbic acid by some mammals, results from an inherited lack of an active form of this enzyme. Sulfhydryl reducing agents have been found to stimulate L-gulonolactone oxidase activity of purified rat and goat enzyme.

Black death: an ascorbic acid deficiency disease in penaeid shrimp

1. 1. The physiological requirement for ascorbic acid (AsA) has been established for two species of penaeid shrimp: Penaeus californiensis (Holmes) and Penaeus stylirostris (Stimpson). 2. 2. The AsA deficiency disease syndrome, called black death disease (BD), has been characterized by melanized lesions in the loose connective tissue under the exoskeleton, on the abdomen, on the carapace, in the gills, and in the foregut and hindgut. 3. 3. Tissue levels of AsA showed a positive correlation with intake of AsA and with change in survival and negatively correlated with occurrence of BD. 4. 4. Experiments demonstrated a statistical advantage ( P < 0.05) in growth and survival in P. californiensis and for growth in P. stylirostris fed diets containing AsA.

Use of Guinea Pigs as Model to Study Galactose-Induced Cataract Formation

Because the dietary requirement for ascorbic acid is similar in humans and guinea pigs, galactose-induced cataract research with the guinea pig as an experimental model instead of the rat might be appropriate and may represent a closer analogy to galactosemic cataract formation in humans. In this study, dietary ascorbic acid was found in all guinea pigs to have a retarding or delaying effect on the development of galactose-induced cataracts.

Effect of Graded Levels of Supplemental Ascorbic Acid in Practical Diets Fed to Rainbow Trout (Salmo gairdneri)

Deficiency symptoms, including anorexia, lethargy, lying prostrate at the bottom of the tank, scoliosis, and lordosis, were noted 20 wk after the start of the experiment in rainbow trout (Salmo gairdneri) held at 15 °C and fed a diet with no supplemental ascorbic acid. The apparent requirement was 40 mg/kg of supplemental ascorbic acid; however, the amount added to trout diets should be in excess of this level due to processing and storage losses and other factors. The ascorbic acid requirement for rainbow trout appears to vary with the age and rate of growth of the trout in that the requirement is higher in young fish. Ascorbic acid was noted to function in the iron metabolism of rainbow trout. Liver and spleen iron levels were correlated with the ascorbic acid level in the diet and suggest either a redistribution of iron stores due to impaired release of iron from reticuloendothelial stores or an increase in the efficiency of intestinal iron absorption. Scorbutic trout developed a gradual but progressive anemia. Key words: ascorbic acid, rainbow trout, vitamin requirement, iron, mineral metabolism, anemia

Dietary ascorbic acid requirement of rainbow trout for growth and collagen formation.

Young rainbow trout given an ascorbic acid-free diet from the age of 6 weeks showed slight but significant decreases in the hydroxyproline content and the hydroxyproline/proline ratio of the collagen fraction in their skin and bone before they developed the apparent symptoms of scurvy, such as lordosis, scoliosis, and exophthalmus, after 21-24 weeks. These results indicate that the scurvy symptoms, such as skeletal deformities, should be attributed to impaired collagen formation arising from lack of ascorbic acid. On the other hand, older rainbow trout given an ascorbic acid-free diet from the age of 10 months showed no abnormal response with respect to growth. The formation of their skin collagen proceeded normally. But these trout showed impaired collagen formation in skin wound repair. These results suggest that the requirement for ascorbic acid decreases as the fish grow older, while increased amounts of dietary ascorbic acid are required for rapid growth and for wound repair. It is concluded that rainbow trout irrespective of age require dietary ascorbic acid to maintain their health.

Ascorbic acid requirement for biosynthesis of hydroxyproline-containing proteins in plants

Ascorbic acid requirement for biosynthesis of hydroxyproline-containing proteins in plants

Further comments on the ascorbic acid requirement.

Recommended Daily Allowances (US RDA) of the Food and Drug Administration for ascorbic acid are higher than Recommended Dietary Allowances (set by the Food and Nutrition Board) for adults. There is a 6-fold margin between the requirement to prevent scurvy and the US RDA. The high requirement reported for the rhesus monkey may be needed to compensate for oxidative catabolism of ascorbic acid in this species. The rate of production of ascorbic acid, in mammals that synthesize it has been listed as 3-19 g/70 kg per day. If this high rate of synthesis represents the requirement of such animals, mutations that caused a loss of ascorbic-acid-synthesizing ability would be eliminated by natural selection on diets that failed to supply these large quantities. The loss of ascorbic-acid-synthesizing ability by human beings could indicate a low requirement, which has enabled our species to spread to regions of the earth where dietary sources of ascorbic acid are poor.

Relationships of ascorbic acid to pregnancy, and oral contraceptive steroids.

The 1974 RDA is 60 mg per day for pregnant women and 80 mg per day for lactating women. In the present study an attempt was made to simulate this intake in the guinea pig and study reproduction performance in relation to guinea pigs fed chronically low and high levels. In animals that conceived and carried the young to term, all 3 dietary levels of ascorbic acid appeared to be adequate for maintaining viability of fetuses and of offspring, and for growth of offspring during the nursing period. The chronically low intake level was not adequate for growth after weaning. The control group was superior to the chronically low-intake group but inferior to the high-intake group in conceiving, producing litters, and carrying litters to term. The level of intake in the control group was inadequate to maintain tissue stores. Even the high intake was inadequate to maintain some tissues at saturation levels. The results suggest that the requirement for ascorbic acid during pregnancy and lactation has been markedly underestimated.

Metabolism of ascorbic acid and ascorbic-2-sulfate in man and the subhuman primate.

Man does not catabolize ascorbate to CO2, whereas the monkey does catabolize ascorbate and ascorbate sulfate to CO2 when these compounds are given orally. However, it takes the same length of time to produce frank scurvy in both man and the monkey, thus indicating that the comparative storage, rate of use, and mode of metabolism of ascorbate is similar in both species. Preliminary feeding and isotope studies conducted on monkeys are in agreement with the fact that only a small amount of labeled ascorbate or ascorbate sulfate equilibrated with body stores. These results are in agreement with published ascorbic acid requirements of 10 mg/kg body weight. In our experiments, 250 mg/day had to be fed to a 10-kg monkey to completely clear all signs of scurvy and return blood ascorbate levels to normal. Ascorbic acid administered intravenously to monkeys appears to equilibrate completely with the ascorbate pool(s). Ascorbate sulfate was found to be a urinary metabolite of both ascorbic-1-14C acid and ascorbic-6-14C acid fed orally to monkeys.

Growth and Ascorbic Acid Metabolism in Rats and Guinea Pigs Fed Cereal Diets

The nutritional values of the whole grain principal cereals, namely, wheat, rice, corn, and a millet bajra, were investigated by growth studies and studies on ascorbic acid metabolism in rats and guinea pigs. Growth was markedly retarded by feeding the rats unfortified whole grain cereals. Among the whole grain cereals, rice provided the lowest nutritional value, and the cooking of rice affected the nutritional value further. In weanling rats, ascorbic acid synthesis at the subcellular level was inhibited, and tissue storage of ascorbic acid was decreased in rats fed whole grain cereals. In guinea pigs fed whole grain cereals, the utilization of ascorbic acid was increased. Ascorbic acid supplementation at various levels indicated that the requirement for ascorbic acid increased five times in guinea pigs fed whole grain cereals. The increased intake of the vitamin was not needed when the whole grain cereals were enriched with 15% casein.

Are Recommended Daily Allowances for Vitamin C Adequate?

Recommended daily allowances, U.S.A., for ascorbic acid are several times the minimum daily requirement of about 10 mg to prevent clinical symptoms in adults. The recommended daily allowances reflect the levels of ascorbic acid required to produce tissue saturation in human beings, so that higher doses are promptly excreted in the urine. In various investigations, responses to ascorbic acid were not obtained under conditions where the intake was considerably lower than the recommended daily allowances, but higher than the level needed to prevent clinical symptoms of ascorbic acid deficiency. The human ascorbic acid requirement cannot be calculated by a linear extrapolation from guinea pigs per kg of body weight because guinea pigs are much smaller than human beings and, hence, their metabolism is more rapid per unit of body weight. Evolutionary loss of ascorbic-acid-synthesizing ability may be a neutral change that was incorporated by genetic drift.

Inactivation of Hormone-sensitive Lipase from Adipose Tissue with Adenosine Triphosphate, Magnesium, and Ascorbic Acid

Abstract Inactivation of ammonium sulfate-precipitated lipase requires, in addition to ATP and Mg2+ion, a dialyzable factor present in homogenates of adipose tissue (Tsai, S.-C., and Vaughan, M. (1972) J. Biol. Chem. 247, 6253–6258) and liver which has now been identified as ascorbic acid. It was extracted from acetone powder of rat liver with methanol-water, 70:30, and purified using barium precipitation and ion exchange and paper chromatography. Approximately 3 mg of a fine white powder obtained from 100 g of liver were used for preparation of trimethylsilyl and deuterotrimethylsilyl derivatives with and without prior reaction with diazomethane. Analysis of these with gas chromatography and mass spectrometry led to the conclusion that the factor was ascorbic acid. This was confirmed by analysis of the trimethylsilyl derivative of authentic l-ascorbic acid. The ultraviolet absorption spectrum and chemical characteristics of the isolated material were consistent with this designation. Lipase inactivation was proportional to ascorbic acid concentration in the range of 0.3 to 3 µm in the presence of 2 mm ATP and 4 mm MgCl2. In the absence of the latter, ascorbic acid, like the inactivation factor, did not alter lipase activity. Identification of ascorbic acid as the tissue factor required for Mg2+ATP-dependent inactivation of the hormone-sensitive lipase should facilitate further characterization of this process. In addition, because the requirement for ascorbic acid appears to be rather specific and the effective concentrations low relative to those employed in many other enzymatic systems, these observations may lead to the demonstration of a role for ascorbic acid in reactions of a type not hitherto associated with this compound.

Ascorbic acid and the glycosaminoglycans. An orthomolecular approach to cancer and other diseases.

A new concept of a basic mechanism involved in cell proliferation is presented. It is suggested that cells are normally restrained from proliferating by the highly viscous nature of the intercellular glycosaminoglycans. In order to proliferate, cells must escape from this restraint by depolymerizing the glycosaminoglycans in their immediate environment. This process is accomplished by the release of the enzyme hyaluronidase and is kept in check by physiological hyaluronidase inhibitor. There is some evidence that physiological hyaluronidase inhibitor is an oligoglycosaminoglycan that requires ascorbic acid for its synthesis, and perhaps incorporates residues of ascorbic acid. This hypothesis provides an explanation for the pathogenesis of scurvy. It explains the increased requirement for ascorbic acid that occurs in many cell proliferative diseases, including cancer. It indicates the existence of a basic underlying mechanism in many pathological states and suggests a common pattern of treatment. We conclude that ascorbic acid may have much greater therapeutic value than has been generally assigned to it.

The fractionation of two glucosinolases from Sinapis alba seed by isoelectric focussing

Two distinct glucosinolases were isolated from mature seeds of yellow mustard by isoelectric focussing. One had an absolute requirements for ascorbic acid, had an isoelectric point of pH 5·55 (20°), and was inhibited by temperatures above 45°. The other glucosinolase did not require ascorbic acid, had an isoelectric point of pH 5·0 (20°), and showed a temperature optimum of about 75°. Both glucosinolases liberated pOH benzyl isothiocyanate, glucose and sulphate from pOH benzylglucosinolate. They had identical K m values and did not differ in response to various pH values.

Lognormal Model for Ascorbic Acid Requirements in Man

Results have recently been obtained which call into question the correctness of the minimum daily adult requirement of vitamin C set down by the Food and Drug Administration. In particular, Pauling (1970), Ritzel (1961), and Stone (1967) indicate that large amounts can have a prophylactic effect on the common cold. Also, Gildersleeve (1967), Pauling (1970), and Regnier (1968) indicate that large amounts can abort a cold in its very early stages and suppress the symptoms of a fully developed cold. In experiments with guinea pigs, Williams and Deason (1967) found a twentyfold variation in the amount of vitamin C needed to prevent symptoms of scurvy and concluded there must be at least as much variability in the vitamin C requirement in man. Finally, Bourne (1949), Pauling (1970), and Stone (1966) give entirely distinct arguments that indicate a typical human daily vitamin C requirement for maintenance of full health is on the order of grams, perhaps one to five, rather than milligrams. A number of studies on the relationship of vitamin C to the common cold have been published. Some of them, notably the large-sample studies of Glazebrook and Thomson (1942), Cowan et al (1942), Ritzel (1961), and Gildersleeve (1967) lend some support to the claim that vitamin C does reduce the incidence and severity of colds. Others, notably those of Tebrock et al. (1956) and Walker et al. (1967), seem to support the opposite conclusion. The purpose of this paper is to show that the four affirmative studies mentioned above can be made to fit very neatly a log-normal distribution with large variance. As a result, these studies will be seen not to stand alone but to support one another. In addition, the fitted distribution will lend support to the conclusion of Williams and Deason mentioned above and to the computations by Bourne, Pauling, and Stone of the typical daily amounts of vitamin C required for full health. A random variable is said to have a

Defect in synthesis of epinephrine in premature infants with tyrosinemia

The relationship between elevated serum tyrosine levels and urinary catecholamine excretion was studied in 17 premature infants and in one patient with tyrosinosis. In premature infants with serum tyrosine levels greater than 10 mg per cent urinary excretion of epinephrine was decreased, norepinephrine excretion was unchanged, and VMA (Pisano) was increased. In contrast, in patients with tyrosinosis excretion of epinephrine is not decreased and may even be increased. This suggests that the decreased excretion of epinephrine in the premature infants with elevated serum tyrosine is not a result of the increased serum tyrosine level. The decreased epinephrine excretion, like the elevated serum tyrosine, may be another metabolic effect of increased ascorbic acid requirements of premature infants.

Ascorbic acid requirement of mature horses.

Ascorbic acid requirement of mature horses.

Supply of ascorbic acid requirement in chronic kidney insufficiency and its modification by means of extracorporeal hemodialysis

Bei Kranken mit chronischer Niereninsuffizienz konnte trotz ausreichender Vitamin C-Zufuhr mit der Nahrung eine unter der Norm liegende Ascorbinsaurekonzentration im Serum nachgewiesen werden. Zu cinem weiteren Konzentrationsabfall kam es unter der extrakorporalen Hamodialyse.