scholarly journals Absorption of labelled vitamin A in children during infection

1972 ◽  
Vol 27 (2) ◽  
pp. 299-304 ◽  
Author(s):  
B. Sivakumar ◽  
Vinodini Reddy
Keyword(s):  
Vitamin A ◽  
Intestinal Absorption ◽  
Respiratory Infection ◽  
Vitamin A Deficiency ◽  
Retinyl Acetate ◽  
Normal Children ◽  
Poor Communities

1. The intestinal absorption of [11,12 3H2] retinyl acetate was studied in five apparently normal children, eight children with respiratory infection and three with gastroenteritis.2. The absorption of vitamin A was significantly lower in children with respiratory infection or gastroenteritis than in normal children.3. In the light of these observations, it is suggested that repeated attacks of infections may significantly contribute to the prevalence of vitamin A deficiency in children of poor communities.

scholarly journals Vitamin A deficiency alters airway resistance in children with acute upper respiratory infection

2012 ◽  
Vol 48 (5) ◽  
pp. 481-489 ◽  
Author(s):  
Cleia T. Amaral ◽  
Núbia N. Pontes ◽  
Bruna L.L. Maciel ◽  
Hugo S.M. Bezerra ◽  
Ana Nataly A.B. Triesta ◽  
...  
Keyword(s):  
Vitamin A ◽  
Respiratory Infection ◽  
Airway Resistance ◽  
Vitamin A Deficiency ◽  
Upper Respiratory Infection ◽  
Upper Respiratory

scholarly journals Lysozyme activity in plasma and leucocytes in malnourished children

1974 ◽  
Vol 32 (2) ◽  
pp. 313-316 ◽  
Author(s):  
M. Mohanram ◽  
Vinodini Reddy ◽  
S. Mishra
Keyword(s):  
Enzyme Activity ◽  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Lysozyme Activity ◽  
Normal Children ◽  
Control Value ◽  
Malnourished Children ◽  
Resistance To Infection ◽  
Ocular Signs

1. Lysozyme activity was estimated in plasma and leucocytes of twelve children suffering from kwashiorkor, thirteen children with ocular signs of vitamin A deficiency and ten apparently normal children acting as controls.2. The results showed that the activity of lysozyme in leucocytes was significantly reduced in children with kwashiorkor and in vitamin A-deficient children. Following therapy, the levels of the enzyme in leucocytes were restored to normal.3. The initial enzyme activity in the plasma of both groups of children did not differ significantly from the control value, and was not significantly changed after treatment.4. It is suggested that the decreased activity of lysozyme is one of the factors responsible for diminished resistance to infection generally observed in malnourished children.

Retention of a Single Oral Massive Dose of Vitamin A

1973 ◽  
Vol 45 (2) ◽  
pp. 233-237
Author(s):  
Sheila M. Pereira ◽  
Almas Begum
Keyword(s):  
Vitamin A ◽  
Intestinal Absorption ◽  
School Children ◽  
Retinyl Palmitate ◽  
Retinyl Acetate ◽  
Massive Dose

1. Six pre-school children with normal intestinal absorption were given 100000 μg of retinyl palmitate and 14·4 μCi of [11,12-3H]retinyl acetate. 2. The absorption, excretion and retention of the label were determined. 3. The children retained 23–54% of the label. 4. The inefficacy of the massive dose as a prophylaxis against deficiency is discussed.

scholarly journals Effects of dietary vitamin A intake on acrosin- and plasminogen-activator activity of ram spermatozoa

Reproduction ◽  
2005 ◽  
Vol 129 (6) ◽  
pp. 707-715 ◽  
Author(s):  
I A Zervos ◽  
M P Tsantarliotou ◽  
G Vatzias ◽  
P Goulas ◽  
N A Kokolis ◽  
...  
Keyword(s):  
Vitamin A ◽  
Plasminogen Activator ◽  
Proteolytic Enzymes ◽  
Vitamin A Deficiency ◽  
Plasminogen Activators ◽  
The Body ◽  
Dietary Vitamin ◽  
Retinyl Acetate ◽  
Plasminogen Activator Activity ◽  
Group B

Acrosin and plasminogen activators are proteolytic enzymes of ram spermatozoa that play an essential role in the induction of the acrosome reaction, as well as the binding of spermatozoa to the oocyte and their penetration through the layers that surround the oocyte. Since vitamin A can alter gene expression in various tissues, testis included, this study was undertaken to evaluate the possible effect of vitamin A intake on acrosin- and plasminogen-activator activity. During a 20-week experiment, 15 rams of the Greek breed Karagouniki, divided to three groups, received different amounts of vitamin Aper osin retinyl acetate capsules (group A, controls, 12 500 iu/animal per day; group B, 50 000 iu/animal per day; group C, 0 iu/animal per day up to the 13th week, then 150 000 iu/animal per day until the end of the experiment). Acrosin- and plasminogen-activator activity were determined by spectrophotometric methods. Vitamin A was determined in blood plasma by HPLC. No statistical differences were detected regarding the body weight of the rams or the qualitative and quantitative parameters of their ejaculate throughout the whole experiment. No statistically significant alterations of enzyme activity were detected in group B. In group C, both enzyme activities started declining in week 9. Compared with controls, maximum reduction for acrosin was 49% on week 11 and for plasminogen activators 51% in week 14. Activities returned to normal rates after vitamin A resupplementation. To date, the main result of vitamin A deficiency was known to be arrest of spermatogenesis and testicular degeneration. A new role for vitamin A may be suggested, since it can influence factors related to male reproductive ability before spermatogenesis is affected.

scholarly journals Effect of vitamin A deprivation on the cholesterol side-chain cleavage enzyme activity of testes and ovaries of rats (Short Communication)

1973 ◽  
Vol 136 (1) ◽  
pp. 221-223 ◽  
Author(s):  
M. Jayaram ◽  
S. K. Murthy ◽  
J. Ganguly
Keyword(s):  
Enzyme Activity ◽  
Vitamin A ◽  
Short Communication ◽  
Normal Values ◽  
Vitamin A Deficiency ◽  
Side Chain ◽  
Retinyl Acetate ◽  
Side Chain Cleavage ◽  
Chain Cleavage ◽  
Cleavage Enzyme

The cholesterol side-chain cleavage enzyme activity is decreased considerably at the mild stage of vitamin A deficiency in rat testes and ovaries and the decrease in activity becomes more pronounced with progress of deficiency. Supplementation of the deficient rats with retinyl acetate, but not retinoic acid, restores the enzyme activity to normal values. The cholesterol side-chain cleavage enzyme of adrenals is not affected by any of the above treatments.

scholarly journals The retinol requirements of rats for spermatogenesis and vision

1969 ◽  
Vol 23 (3) ◽  
pp. 619-626 ◽  
Author(s):  
W.A. Coward ◽  
J.McC. Howell ◽  
J.N. Thompson ◽  
G. A. J. PITT
Keyword(s):  
Retinoic Acid ◽  
Vitamin A ◽  
Beneficial Effect ◽  
General Health ◽  
Vitamin A Deficiency ◽  
Experimental Period ◽  
Normal Vision ◽  
Retinyl Acetate ◽  
Deficient Diet ◽  
Histological Appearance

1. Hooded rats were fed from weaning on a basal retinol-deficient diet containing retinoic acid. Such a diet maintains growth and general health but does not prevent the appearance of lesions associated with vitamin A deficiency in the retina and testis. Some animals were also given supplements of retinol averaging 0.1, 0.25, 1 or 5 μg retinyl acetate per day. Rats were killed at intervals up to 28 weeks after weaning. The weights of the testes and the histological appearance of the testes and epididymides indicated that 5 μg retinyl acetate per day had maintained spermatogenesis throughout the experimental period. Doses averaging 1 μg retinyl acetate per day were only partially effective and the two smaller doses had little beneficial effect.2. In a second similar experiment rats were given doses of retinyl acetate averaging 0.25, 0.5, 1, 2 or 100 μg per day. Measurements of the electroretinogram thresholds of the rats indicated that a dose of 1 μg retinyl acetate per day maintained mainly normal vision until the end of the experiment 29 weeks after weaning. Additional histological observations made 21 weeks after weaning showed that this dose level had not maintained spermatogenesis but that doses of 2 μg retinyl acetate per day had been effective.3. The experiments show that the differing functions of vitamin A in spermatogenesis and vision are reflected in the hooded rat in differences in the dietary retinol levels needed to maintain these processes.

scholarly journals Carotene dioxygenase (EC 1. 13. 11. 21) activity in rat intestine: effects of vitamin A deficiency and of pregnancy

1986 ◽  
Vol 56 (1) ◽  
pp. 115-122 ◽  
Author(s):  
Laurence Villard ◽  
C. J. Bates
Keyword(s):  
Vitamin A ◽  
Vitamin A Deficiency ◽  
Statistical Significance ◽  
Supernatant Fraction ◽  
Retinyl Acetate ◽  
Vitamin A Status ◽  
Severe Deficiency ◽  
Weanling Rats ◽  
The Difference ◽  
Tissue Vitamin

1. Female weanling rats were fed on a purified diet containing either no vitamin A, apart from traces present in casein (deficient groups), or the same diet containing 1.55 mg retinol as retinyl acetate/kg (control groups). In one experiment the deficient groups were given 1 μg retinol/d after 10 weeks, to permit successful reproduction under conditions of marginal vitamin A status. A proportion were mated at 11 weeks after weaning, and fetal development was permitted for 7 d or for 20 d before killing.2. Carotene dioxygenase (EC 1. 13.11.21) activity was measured in a supernatant fraction from intestinal mucosal scrapings. For each group, activity was 20–30% greater in the vitamin-A-deficient animals than in the controls, and the difference reached statistical significance for the virgin and 7 d pregnant animals in the first experiment (severe deficiency) and for the 20 d pregnant animals in the second experiment (less-severe deficiency).3. It is suggested that low tissue vitamin A levels may feedback to increase carotene dioxygenase activity, by mechanisms at present unknown, presumably to ensure a more efficient use of precursor dietary carotenoids.

α and β-Retinyl acetate reverse metaplasias of vitamin A deficiency in hamster trachea in organ culture

Nature ◽  
1974 ◽  
Vol 250 (5461) ◽  
pp. 64-66 ◽  
Author(s):  
GERALD H. CLAMON ◽  
MICHAEL B. SPORN ◽  
JOSEPH M. SMITH ◽  
UMBERTO SAFFIOTTI
Keyword(s):  
Vitamin A ◽  
Organ Culture ◽  
Vitamin A Deficiency ◽  
Retinyl Acetate ◽  
Hamster Trachea

scholarly journals Impaired T lymphocyte immune response in vitamin A depleted rats and chicks

1989 ◽  
Vol 62 (2) ◽  
pp. 439-449 ◽  
Author(s):  
Aharon Friedman ◽  
David Sklan
Keyword(s):  
Immune Response ◽  
Vitamin A ◽  
Immune Responses ◽  
T Lymphocyte ◽  
Vitamin A Deficiency ◽  
Retinyl Acetate ◽  
Vitamin A Status ◽  
Severe Impairment ◽  
Lymphocyte Activity

Vitamin A deficiency results in decreased immune responses; the objective of the present study was to investigate the involvement of T lymphocytes in the depression of immune responses resulting from vitamin A depletion. This objective was achieved by evaluating antigen-specific T lymphocyte proliferative responses in vitro as vitamin A depletion developed. The evaluation was performed in both rat and chick to examine the generality of immune effects due to vitamin A depletion. Our findings show that vitamin A depletion led to severe impairment of T lymphocyte activity in both animal models, and that this was directly related to the vitamin A status in both species. Immune response impairment was found to precede other manifestations of vitamin A deficiency, and was rapidly corrected by feeding retinyl acetate boluses. This implied a possible regulatory, rather than constitutive, role of vitamin A in immune responsiveness.

scholarly journals Effect of vitamin A nutritional status on the ribonucleic acids of liver, intestinal mucosa and testes of rats

1977 ◽  
Vol 166 (3) ◽  
pp. 339-346 ◽  
Author(s):  
M Jayaram ◽  
J Ganguly
Keyword(s):  
Molecular Weight ◽  
Retinoic Acid ◽  
Vitamin A ◽  
Nutritional Status ◽  
Intestinal Mucosa ◽  
Vitamin A Deficiency ◽  
Retinyl Acetate ◽  
Ribonucleic Acids ◽  
Appreciable Increase ◽  
Acceptor Activity

1. Vitamin A deficiency led to an increase in the oligonucleotide fraction of testes and intestinal mucosa of rats at the expense of high-molecular-weight RNA and 4S RNA, but no such changes were observed in the liver. Retinyl acetate supplementation reversed these effects in both tissues, whereas retinoic acid supplementation was almost equally effective in the mucosa but virtually ineffective in the testes. The ribonuclease activities of all the tissues remained unaffected by the above treatments. 2. The effect of vitamin A deprivation on the acceptor activity of the tRNA of the testes and intestinal mucosa was more pronounced than on the liver tRNA. The testes and mucosal tRNA of the retinoic acid-supplemented rats showed significantly lower charging capacity as compared with the retinyl acetate-supplemented ones. Here also no significant effect was observed on the liver tRNA. 3. Vitamin A deficiency caused a decrease in the percentage of poly(A) in RNA of the mucosa and testes, but not in the liver RNA. The poly(A) contents of both tissues were brought to normal by retinyl acetate supplementation; treatment with retinoic acid led to an appreciable increase in poly(A) in the mucosa, but considerably less increase in poly(A) in the testes. 4. The incorporation of H332PO4 into the rRNA and tRNA of the testes was lowered by vitamin A deficiency, but no such effects was observed in the liver RNA.

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