Effect of dietary vitamin A on the mixed function oxidases and the pneumotoxicity of 3-methylindole in goats

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.

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.


1999 ◽  
Vol 40 (5) ◽  
pp. 824-829 ◽  
Author(s):  
Monica V. Kumar ◽  
Gregory D. Sunvold ◽  
Philip J. Scarpace

2020 ◽  
Vol 27 (1) ◽  
Author(s):  
K. Walweel ◽  
K. Skeggs ◽  
A. C. Boon ◽  
L. E. See Hoe ◽  
M. Bouquet ◽  
...  

Abstract Background A lung transplant is the last resort treatment for many patients with advanced lung disease. The majority of donated lungs come from donors following brain death (BD). The endothelin axis is upregulated in the blood and lung of the donor after BD resulting in systemic inflammation, lung damage and poor lung graft outcomes in the recipient. Tezosentan (endothelin receptor blocker) improves the pulmonary haemodynamic profile; however, it induces adverse effects on other organs at high doses. Application of ex vivo lung perfusion (EVLP) allows the development of organ-specific hormone resuscitation, to maximise and optimise the donor pool. Therefore, we investigate whether the combination of EVLP and tezosentan administration could improve the quality of donor lungs in a clinically relevant 6-h ovine model of brain stem death (BSD). Methods After 6 h of BSD, lungs obtained from 12 sheep were divided into two groups, control and tezosentan-treated group, and cannulated for EVLP. The lungs were monitored for 6 h and lung perfusate and tissue samples were processed and analysed. Blood gas variables were measured in perfusate samples as well as total proteins and pro-inflammatory biomarkers, IL-6 and IL-8. Lung tissues were collected at the end of EVLP experiments for histology analysis and wet-dry weight ratio (a measure of oedema). Results Our results showed a significant improvement in gas exchange [elevated partial pressure of oxygen (P = 0.02) and reduced partial pressure of carbon dioxide (P = 0.03)] in tezosentan-treated lungs compared to controls. However, the lungs hematoxylin–eosin staining histology results showed minimum lung injuries and there was no difference between both control and tezosentan-treated lungs. Similarly, IL-6 and IL-8 levels in lung perfusate showed no difference between control and tezosentan-treated lungs throughout the EVLP. Histological and tissue analysis showed a non-significant reduction in wet/dry weight ratio in tezosentan-treated lung tissues (P = 0.09) when compared to control. Conclusions These data indicate that administration of tezosentan could improve pulmonary gas exchange during EVLP.


Author(s):  
G Bhanuprakash Reddy ◽  
Raghu Pullakhandam ◽  
Santu Ghosh ◽  
Naveen K Boiroju ◽  
Shalini Tattari ◽  
...  

ABSTRACT Background Biochemical vitamin A deficiency (VAD) is believed to be a serious public health problem (low serum retinol prevalence >20%) in Indian children, justifying universal high-dose vitamin A supplementation (VAS). Objective To evaluate in Indian children younger than 5 y the risk of biochemical VAD from the Comprehensive National Nutrition Survey, as well as dietary vitamin A inadequacy and excess over the tolerable upper limit of intake (TUL) from national and subnational surveys, factoring in fortification and VAS. Methods Child serum retinol data, corrected for inflammation, were examined to evaluate national- and state-level prevalence of VAD. Simultaneously, dietary intakes from the National Sample Survey Office and the National Nutrition Monitoring Bureau were examined for risk of dietary vitamin A deficiency against its average requirement (AR) derived for Indian children. Theoretical estimates of risk reduction with oil and milk vitamin A fortification were evaluated along with the risk of exceeding the TUL, as well as when combined with intake from VAS. Results The national prevalence of biochemical VAD measured in 9563 children was 15.7% (95% CI: 15.2%, 16.3%), and only 3 states had prevalence significantly >20%. The AR of vitamin A was 198 and 191 µg/d for boys and girls; the risk of dietary inadequacy was ∼70%, which reduced to 25% with oil and milk fortification. Then, the risk of exceeding the TUL was 2% and 1% in 1- to 3-y-old and 4- to 5-y-old children, respectively, but when the VAS dose was added to this intake in a cumulative 6-mo framework, the risk of exceeding the TUL rose to 30% and 8%, respectively. Conclusion The national prevalence of VAD risk is below 20% in Indian children. Because there is risk of excess intake with food fortification and VAS, serious consideration should be given to a targeted approach in place of the universal VAS program in India.


2009 ◽  
Vol 66 (6) ◽  
pp. 751-756 ◽  
Author(s):  
Daniela Ferraz Bacconi Campeche ◽  
Rodrigo Ramos Catharino ◽  
Helena Teixeira Godoy ◽  
José Eurico Possebon Cyrino

Dietary vitamin supplementation decrease stress caused by high stocking density, and boosts immunological system of farmed fish. A studied was carried out to determine vitamin A requirements of Nile tilapia (Oreochromis niloticus) in an all male group (13.8 ± 1.2 g) and a mixed sex population (9.8 ± 2.3 g). Fish stocked in 100-L plastic aquaria (26.0 ± 1.0ºC) were fed to near satiety, twice a day, seven days a week, during 75 days with vitamin A-free, semi-purified diets supplemented with 0; 600; 1,200; 1,800; 2,400; 3,000; 3,600; 4,200; 4,800 and 5,400 International Units (IU) of retinyl palmitate (30% vitamin A) per kg of diet in a completely randomized experimental design, factorial arrangement 2c10 (n = 4). Deficiency signs of vitamin A were observed in fish fed 0 to 1.200 IU vitamin A kg-1 diet; moderate signs were observed in fish fed diets with 1.800 to 3.600 IU vitamin A kg-1 diet; no interactions group*level (p < 0.05) were detected. Dietary levels of vitamin A up to 5.400 IU kg-1 influenced final weight and weight gain of fish (p < 0.05), but did not influence feed consumption (p > 0.05). A group effect was observed regarding all performance variables (p < 0.0001). Quantification of hepatic retinol (HPLC) detected vitamin A only in fish fed 5.400 IU retinol kg-1 of diet, therefore characterizing that dietary retinol was used and stored. The quantity of 5.400 IU of retinol kg-1 of diet is recommended for adequate nutrition of Nile tilapia.


2005 ◽  
Vol 289 (1) ◽  
pp. L104-L110 ◽  
Author(s):  
Mark R. Looney ◽  
Claudio Sartori ◽  
Santanu Chakraborty ◽  
Paul F. James ◽  
Jerry B. Lingrel ◽  
...  

Impaired epithelial sodium channel function predisposes to delayed resorption of pulmonary edema and more severe experimental lung injury, whereas even a small fraction of the normal Na-K-ATPase activity is thought to be sufficient to maintain normal ion transport. However, direct proof is lacking. Therefore, we studied baseline and cAMP stimulated alveolar fluid clearance (AFC) in mice with a 50% decrease in lung protein expression of the α1- and/or α2-subunit of the Na-K-ATPase. There was no difference in basal and stimulated AFC in α1+/− or α2+/− mice compared with wild-type littermates. Also, the compound heterozygous mice (α1+/−/α2+/−) had normal basal AFC. However, the combined α1+/−/α2+/− mice showed a significant decrease in cAMP-stimulated AFC compared with wild-type littermates (11.1 ± 1.0 vs. 14.9 ± 1.8%/30 min, P < 0.001). When exposed to 96 h of >95% hyperoxia, the decrease in stimulated AFC in the α1+/−/α2+/− mice was not associated with more lung edema compared with wild-type littermates (lung wet-to-dry weight ratio 6.6 ± 0.9 vs. 5.9 ± 1.1, respectively; P = not significant). Thus a 50% decrease in protein expression of the α1- or α2-subunits of the Na-K-ATPase does not impair basal or stimulated AFC. However, a 50% protein reduction in both the α1- and α2-subunits of the Na-K-ATPase produces a submaximal stimulated AFC, suggesting a synergistic role for α1- and α2-subunits in cAMP-dependent alveolar epithelial fluid clearance.


2001 ◽  
Vol 73 (3) ◽  
pp. 433-441 ◽  
Author(s):  
T. Tokuda ◽  
S. Kono ◽  
T. Fujihara

AbstractThe objective of this study was to examine the effect of dietary vitamin A (retinol) on leptin in cattle. The relationship between plasma leptin and insulin was also examined. The experiment studies 16 9-month-old steers over the following 20-month fattening period. Four treatment diets were given to four steers in each of four groups. Cattle in treatment A were given a diet high in vitamin A (9000 to 10500 µg/day) throughout the experiment. Cattle in treatment B were given a diet low in vitamin A (300 to 4500 µg/day) for 0 to 10 months, after that they were given the high vitamin A diet during the period 10 to 20 months. Cattle in treatment C were given the low vitamin A diet for 0 to 14 months, after that they were given the high vitamin A diet for the period 14 to 20 months. Cattle in treatment D were given the low vitamin A diet throughout the experiment. Plasma samples were collected at 2-month intervals during the experiment to determine the plasma leptin, insulin and vitamin A concentrations. Plasma leptin concentration significantly increased over the fattening period (P< 0·001) but did not differ between the treatments (P> 0·05). Plasma leptin concentration was positively correlated with insulin concentration (r = 0·44,P< 0·001), although it was not correlated with plasma vitamin A concentration (r = –0·01,P> 0·05). It was concluded that dietary vitamin A in cattle does not affect plasma leptin concentration.


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