Teratogenicity of a Single Oral Dose of Retinyl Palmitate in the Rat, and the Role of Dietary Vitamin A Status

1996 ◽  
Vol 79 (3) ◽  
pp. 131-135 ◽  
Author(s):  
A. H. Piersma ◽  
W. Bode ◽  
A. Verhoef ◽  
M. Olling
2003 ◽  
Vol 90 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Lena Davidsson ◽  
Pierre Adou ◽  
Christophe Zeder ◽  
Thomas Walczyk ◽  
Richard Hurrell

Retinyl palmitate added to Fe-fortified maize bread has been reported to enhance Fe absorption in adult Venezuelan subjects but not in Western Europeans. It is not known to what extent these results were influenced by differences in vitamin A status of the study subjects. The objective of the present study was to evaluate the influence of retinyl palmitate added to Fe-fortified maize porridge on erythrocyte incorporation of Fe in children with vitamin A deficiency, before and after vitamin A supplementation. Erythrocyte incorporation of Fe-stable isotopes was measured 14 d after intake of maize porridge (2·0 mg Fe added as ferrous sulfate) with and without added retinyl palmitate (3·5 μmol; 3300 IU). The study was repeated 3 weeks after vitamin A supplementation (intake of a single dose of 210 μmol retinyl palmitate; ‘vitamin A capsule’). Vitamin A status was evaluated by the modified relative dose–response (MRDR) technique. Retinyl palmitate added to the test meal reduced the geometric mean erythrocyte incorporation of Fe at baseline from 4·0 to 2·6 % (P=0·008, n 13; paired t test). At 3 weeks after vitamin A supplementation, geometric mean erythrocyte incorporation was 1·9 and 2·3 % respectively from the test meal with and without added retinyl palmitate (P=0·283). Mean dehydroretinol:retinol molar ratios were 0·156 and 0·125 before and after intake of the single dose of 210 μmol retinyl palmitate; ‘vitamin A capsule’ (P=0·15). In conclusion, retinyl palmitate added to the labelled test meals significantly decreased erythrocyte incorporation of Fe in children with vitamin A deficiency at baseline but had no statistically significant effect 3 weeks after vitamin A supplementation. The difference in response to retinyl palmitate added to Fe-fortified maize porridge on erythrocyte incorporation of Fe before and after intake of the vitamin A capsule indicates, indirectly, changes in vitamin A status not measurable by the MRDR technique. The lack of conclusive data on the effect of retinyl palmitate on Fe absorption indicates the complexity of the interactions between vitamin A status, dietary vitamin A and Fe metabolism.


1975 ◽  
Vol 53 (2) ◽  
pp. 256-263
Author(s):  
Bill Woodward ◽  
B. E. March

The variable effect of excessive vitamin A intake on alimentary cholesterolemia was investigated in cockerels of strains of White Leghorns and New Hampshires. With the New Hampshire cockerels, the feeding of 0.5% of dietary cholesterol resulted in greater cholesterolemia when the diet contained 1 700 I.U. of vitamin A per kilogram than when it contained 22 000 I.U. of vitamin A per kilogram. With the White Leghorn cockerels, on the other hand, cholesterolemia was enhanced with the higher level of dietary vitamin A. Absorption of a single oral dose of cholesterol was increased in birds of both breeds when vitamin A had been given previously by injection. In the White Leghorn cockerels the percentage of newly absorbed cholesterol in the hepatic pool was reduced by vitamin A administration, whereas in the New Hampshire cockerels the percentage was increased. It was concluded that excess vitamin A may have divergent effects on alimentary cholesterolemia in chickens of different genetic backgrounds as a result of opposite effects on the liver–blood ratio of a large load of cholesterol.


2003 ◽  
Vol 73 (4) ◽  
pp. 267-273 ◽  
Author(s):  
Barua

This study was carried out to determine how much of a single oral dose of beta-carotene in oil is absorbed and how much of the absorbed dose is converted to retinoids in rats having a vitamin A reserve at the lowest end of adequate status. Weanling rats raised on a vitamin A-deficient diet for four weeks were given a single oral dose of either corn oil or beta-carotene dissolved in corn oil (1.86 mumol). Serum, liver, and the entire digestive tract of the rats were analyzed for carotenoids and retinoids. Results showed that 4 hours after dosing, 1.64 mumol (88%) of the dose of beta-carotene was found intact, with 17.6% found in the stomach, 21% in the small intestine, and 49.3% in the large intestine. A total of 0.28 mumol of newly formed retinoids (expressed as retinyl palmitate) was present in serum, liver, and mucosa of small intestine. The results suggest that a single oral dose of beta-carotene might not be an effective way of raising vitamin A status in rats.


2021 ◽  
pp. 037957212110602
Author(s):  
Mark Pretzel P. Zumaraga ◽  
Jose Maria Reynaldo Apollo Arquiza ◽  
Mae Anne Concepcion ◽  
Leah Perlas ◽  
Ma. Neda Alcudia-Catalma ◽  
...  

Background: The study aimed to identify two beta-carotene 15,15′-monooxygenase (BCMO1) mutations, namely R267S and A379V, and determine their association with vitamin A status among Filipinos 6 to 19 years old respondents of the 2013 Philippine National Nutrition Survey living in the National Capital Region. Materials and Methods: This study followed cross-sectional design. Whole blood specimen was collected in the morning and was used as source of genomic DNA and serum for retinol concentration determination. Fisher exact test was performed to determine whether genotype frequencies were associated to retinol concentrations/vitamin A deficiency status. A level of P < .05 was identified as significant. Results: A total of 693 Filipino children and adolescents were included. Of the 693, there were at least 7.6% who bears the combined mutations for R267S + A379V. Association analysis showed that an inverse relationship exists between the A379V TT variant and vitamin A status. Although the exact role of these identified polymorphisms on retinol/carotenoid metabolism need to be confirmed in dedicated functional studies. Conclusion: This study has identified for the first time the presence of 2 nonsynonymous genetic variants/mutations in the coding region of BCMO1 gene. Interestingly, one of these two variants, the A379V T, was found to be associated with vitamin A status. It is, therefore, warranted to investigate the role of BCMO1 variants for the success of supplementation programs and fortification efforts among vulnerable populations in this region. Genetic variability should be considered for future provitamin A supplementation recommendations among children and adolescents in the Philippines.


2015 ◽  
Vol 8 (4-6) ◽  
pp. 164-173 ◽  
Author(s):  
Katie Goodwin ◽  
Michal Abrahamowicz ◽  
Gabriel Leonard ◽  
Michel Perron ◽  
Louis Richer ◽  
...  

2020 ◽  
Vol 09 (01) ◽  
pp. 30-34
Author(s):  
Muzzain Iqbal ◽  
Sarbjit Singh Chhiber ◽  
Baldev Singh Wazir ◽  
Altaf Umar Ramzan ◽  
Mohammad Saleem Wani

Abstract Objective To analyze role of phosphodiesterase 5 (PDE5) inhibitors on urodynamic parameters in patients with suprasacral spinal cord injury. Materials and Methods This was a prospective observational hospital-based study conducted on a cohort of patients, aged between 18 and 65 years with suprasacral spinal cord injury, who were registered in Department of Neurosurgery/Urology. Cutoff period since injury was 2 years. After taking consent, baseline urodynamic study was performed, which was repeated 2 hours after taking single oral dose of 20 mg tadalafil. Urodynamic parameters such as maximum detrusor filling/voiding pressures, maximum bladder capacity, and bladder compliance before and after taking drug were compared for final results and conclusion. Results Following administration of 20 mg of tadalafil, maximum bladder capacity in mL showed statistically significant improvement from 268.39 ± 130.0 to 298.55 ± 112.0.(p < 0.05). Bladder compliance improved from 18.68 ± 6.4 to 20.25 ± 7.5 mL/cm H2O (p > 0.05). Maximum detrusor filling pressure improved from 36.03 ± 20.54 to 32.90 ± 16.47 cm H2O (p > 0.05). Maximum detrusor voiding pressure improved from 64.65 ± 33.19 to 58.13 ± 20.7 cm H2O (0 > 0.05). In patients with injury above D6 spinal cord level, statistically significant improvement was seen in maximum bladder capacity and bladder compliance after 2 hours of single oral dose of tadalafil (p < 0.05). Conclusion Our study suggests a positive role of PDE inhibitors in improving urodynamic parameters in patients with suprasacral spinal cord injury with improvement in parameters such as bladder capacity, detrusor pressures, and bladder compliance. Because this is a small study group, more studies such as this are required to reach to final conclusion.


1970 ◽  
Vol 39 (2) ◽  
pp. 159-168 ◽  
Author(s):  
P. Goldswain ◽  
E. Dowdle ◽  
Norma Spong ◽  
L. Eales

1. The specific activities of urinary uroporphyrin and coproporphyrin were measured as functions of time following the administration of a single oral dose of [4-14C] δ-aminolaevulic acid (ALA) to six patients with symptomatic porphyria and one control subject. 2. The peak specific activity of coproporphyrin preceded that of uroporphyrin in all subjects studied and exceeded that of uroporphyrin in the patients with symptomatic porphyria. 3. These results are interpreted as indicating the existence of two distinct metabolic pathways in the liver for the disposal of ALA, rather than as contradicting the generally accepted role of uroporphyrinogen as a precursor of coproporphyrinogen.


1983 ◽  
Vol 61 (8) ◽  
pp. 816-821 ◽  
Author(s):  
F. E. Burley ◽  
T. M. Bray

To determine the effects of dietary vitamin A on the activity of the mixed function oxidase (MFO) system and on the susceptibility to 3-methylindole (3MI)-induced respiratory disease, goats were fed a high (supplemented with 12 000 IU retinyl palmitate/kg) or a low (no supplementation) vitamin A diet for 14 weeks. Four animals in each dietary group were then challenged with [14C]3MI. The remaining four animals served as controls. Enzyme assays were performed and severity of the 3MI-induced lung damage was scored. Consumption of the low vitamin A diet resulted in a significant reduction in the liver and lung contents of vitamin A; however, serum concentration of vitamin A was unaffected. High vitamin A supplementation did not alter the activity of the MFO system. Clinical signs, lung – body weight ratio and wet – dry weight ratio of the lungs of 3MI-infused goats were not significantly different; however, in the low vitamin A goats, the microscopic lesions such as the extent of alveolar epithelial hyperplasia were judged to be significantly more severe than those observed in the high vitamin A goats.


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