Developmental changes in circulatory vitamin A (retinol) and its transport proteins in free-ranging harbour seal (Phoca vitulina) pups

2000 ◽  
Vol 78 (10) ◽  
pp. 1862-1868 ◽  
Author(s):  
Wendy Simms ◽  
Peter S Ross
Keyword(s):  
Vitamin A ◽  
Marine Mammals ◽  
Environmental Contaminants ◽  
Phoca Vitulina ◽  
Transport Proteins ◽  
Developmental Changes ◽  
Harbour Seal ◽  
Retinol Binding Protein ◽  
Free Ranging ◽  
The Impact

Although vitamin A (retinol) levels are highly regulated within individual organisms, natural (e.g., age, sex, disease) and anthropogenic (e.g., environmental contaminants) factors can affect the dynamics of this essential nutrient. In this study, we examined developmental changes in the circulatory vitamin A system of free-ranging harbour seal (Phoca vitulina) pups by collecting serial blood samples from healthy known-age animals throughout their nursing period. While harbour seal pups were born with relatively low levels of circulatory retinol (144.4 ± 13.9 µg/L), nursing animals more than doubled these levels within 2 days (385.0 ± 46.9 µg/L), and levels continued to rise more gradually until weaning (431.0 ± 35.8 µg/L). Animals that were not nursing, such as orphaned (184.4 ± 34.2 µg/L), fasted (347.0 ± 14.4 µg/L), and weaned (204.5 ± 38.5 µg/L) pups, had significantly lower circulatory retinol levels. Despite the developmental changes observed in total retinol, the concentration of retinol bound by its transport proteins, retinol binding protein and transthyretin, remained relatively constant throughout the nursing period. This suggests that, like most mammals, the delivery of retinol to target tissues is highly regulated in harbour seal pups. Furthermore, the high concentrations of circulatory retinol observed in harbour seal pups may serve to saturate transport proteins, ensuring a steady delivery of vitamin A to target tissues during a period of potentially variable supply. Understanding how natural factors affect circulatory retinol and its transport proteins is an important facet of assessing the impact of environmental contaminants on vitamin A dynamics in marine mammals.

Vitamin A physiology in the precocious harbour seal (Phoca vitulina): a tissue-based biomarker approach

2002 ◽  
Vol 80 (9) ◽  
pp. 1511-1519 ◽  
Author(s):  
Lizzy Mos ◽  
Peter S Ross
Keyword(s):  
Vitamin A ◽  
Marine Mammals ◽  
Relevant Information ◽  
Phoca Vitulina ◽  
Retinyl Palmitate ◽  
Harbour Seal ◽  
Natural Processes ◽  
Reproductive Endocrine ◽  
Positive Correlations ◽  
Free Ranging

Vitamin A is a nutrient essential to all mammals for growth and development, as well as for the maintenance of reproductive, endocrine, and immune systems. Environmental contaminant-related disruption of vitamin A has been observed in many wildlife species and can therefore be used as a biomarker of toxic effects. However, the natural processes regulating vitamin A uptake, storage, and distribution among compartments are poorly understood in marine mammals. In this study, 20 young healthy harbour seals (Phoca vitulina) were captured to establish a compartment-based model providing a foundation for a mechanistic understanding of vitamin A physiology and disruption. Vitamin A (retinol, retinyl palmitate, and (or) retinoic acid) was quantified in blood plasma and in biopsy samples of liver, blubber, and skin. Although the highest concentrations of vitamin A were found in liver, blubber represents a more important storage depot, with an estimated 66% of the total retinoid content of the compartments measured. We suggest that vitamin A physiology in the precocious harbour seal has evolved to deal with high vitamin A availability during a short nursing period and to sustain growth during the postweaning fast. Positive correlations in vitamin A concentrations among liver, blubber, and skin support the use of less invasive biopsy sampling of just blubber or skin, which can provide physiologically relevant information in biomarker studies of free-ranging marine mammals.

scholarly journals Livestock-associated meticillin-resistant Staphylococcus aureus in a young harbour seal (Phoca vitulina) with endocarditis

2019 ◽  
Vol 7 (3) ◽  
pp. e000886 ◽  
Author(s):  
Ana Rubio-Garcia ◽  
John W A Rossen ◽  
Jaap A Wagenaar ◽  
Alex W Friedrich ◽  
Jan H van Zeijl
Keyword(s):  
Staphylococcus Aureus ◽  
Marine Mammals ◽  
Aortic Wall ◽  
Bacterial Culture ◽  
Histopathological Examination ◽  
Phoca Vitulina ◽  
Antimicrobial Treatment ◽  
Harbour Seal ◽  
First Time ◽  
Secondary Bacterial Pneumonia

A five-month-old male harbour seal was admitted for rehabilitation to the Sealcentre Pieterburen on November 16, 2015. During initial veterinary examination parasitic pneumonia and secondary bacterial pneumonia were suspected. Therefore, the seal received antiparasitic and antimicrobial treatment and appeared to recover but died unexpectedly after several weeks. Postmortem examination revealed a perforation in the aortic wall and histopathological examination of the aorta revealed mural necrosis with haemorrhage and suppurative to mixed inflammation. Bacterial culture resulted in isolation of a meticillin-resistant Staphylococcus aureus (MRSA) from the pericardial effusion. Subsequent culture of rectal swabs collected at arrival and during rehabilitation showed that the animal was already colonised with MRSA when admitted to the Sealcentre. MRSA has been isolated from marine mammals before, however, to our knowledge this is the first report of MRSA-associated endocarditis in seals and the first time that livestock-associated MRSA is reported in seals.

Dandy–Walker-Like Malformation in a Free-Ranging Atlantic Harbour Seal Pup (Phoca vitulina concolor)

2020 ◽  
Vol 178 ◽  
pp. 41-45
Author(s):  
M.R. Rivard ◽  
J. Díaz-Delgado ◽  
J. Hammond ◽  
J.E. Flower
Keyword(s):  
Phoca Vitulina ◽  
Harbour Seal ◽  
Free Ranging

The retina of the harbour seal, Phoca vitulina

1971 ◽  
Vol 49 (1) ◽  
pp. 19-23 ◽  
Author(s):  
G. S. Jamieson ◽  
H. D. Fisher
Keyword(s):  
Marine Mammals ◽  
Photoreceptor Cell ◽  
Outer Nuclear Layer ◽  
Cell Types ◽  
Phoca Vitulina ◽  
Inner Nuclear Layer ◽  
Horizontal Cells ◽  
Harp Seal ◽  
Harbour Seal ◽  
Retinal Layers

The structure of the retina of the harbour seal, Phoca vitulina richardii, is described. It is shown that the retina of the harbour seal is similar to that of the harp seal, in that it shows little zonation of the inner nuclear layer, possesses large horizontal cells, and has similar nuclear densities within the different retinal layers throughout the retina. The outer nuclear layer is also the thickest of all the retinal layers. Two types of photoreceptor cell, types B and C, were observed with a ratio of roughly 1:23 respectively. This ratio, along with a well-developed and extensive tapetum, indicates a highly light-sensitive retina. The existence of retinal folding in marine mammals is also questioned and discussed.

Uptake of vitamin A in macrophages from physiologic transport proteins: role of retinol-binding protein and chylomicron remnants

1999 ◽  
Vol 10 (6) ◽  
pp. 345-352 ◽  
Author(s):  
Egil Hagen ◽  
Anne M Myhre ◽  
Sigbjørn Smeland ◽  
Bente Halvorsen ◽  
Kaare R Norum ◽  
...  
Keyword(s):  
Vitamin A ◽  
Binding Protein ◽  
Transport Proteins ◽  
Retinol Binding Protein ◽  
Chylomicron Remnants

scholarly journals Subclinical inflammation affects iron and vitamin A but not zinc status assessment in Senegalese children and Cambodian children and women

2018 ◽  
Vol 21 (7) ◽  
pp. 1266-1277 ◽  
Author(s):  
Marion Fiorentino ◽  
Marlène Perignon ◽  
Khov Kuong ◽  
Chhoun Chamnan ◽  
Jacques Berger ◽  
...  
Keyword(s):  
Vitamin A ◽  
Reference Group ◽  
Reproductive Age ◽  
Retinol Binding Protein ◽  
Vitamin A Status ◽  
Micronutrient Status ◽  
Status Assessment ◽  
Zn Status ◽  
Nutritional Studies ◽  
The Impact

AbstractObjectiveTo assess the impact of the acute-phase response (APR) during inflammation on Fe, Zn and vitamin A biomarkers to allow accurate evaluation of micronutrient status in populations.DesignFerritin (FER), soluble transferrin receptor (TfR), retinol-binding protein (RBP), Zn, α1-acid glycoprotein and C-reactive protein concentrations were measured. Correction factors (CF) for each biomarker were calculated as the ratio for groups at different stages of inflammationv. the reference group without inflammation.Setting/SubjectsSenegalese (n594) and Cambodian schoolchildren (n2471); Cambodian women of reproductive age (n2117).ResultsTfR was higher during the incubation phase (CF=1·17) and lower during early and late convalescence (CF=0·87 and 0·78). FER was higher during all phases (CF=0·83, 0·48 and 0·65, respectively). RBP was higher during incubation (CF=0·88) and lower during early convalescence (CF=1·21). No effect of inflammation on Zn status was found.ConclusionsInflammation led to overestimation of Fe status and underestimation of vitamin A status. The response of the biomarker for vitamin A status to inflammation depended on the vitamin A status of the populations. Surprisingly, the assessment of Zn status was hardly affected by inflammation. Different phases of the APR had opposite effects on the assessment of Fe status using TfR. More research is needed to define the correct methods to adjust for inflammation in nutritional studies.

scholarly journals Flupenthixol and cefotiam: effects on vitamin A metabolism in rats

2004 ◽  
Vol 92 (4) ◽  
pp. 597-605 ◽  
Author(s):  
Rainer Schindler ◽  
Tanja Fielenbach ◽  
Gerhard Rave
Keyword(s):  
Vitamin A ◽  
Retinol Binding Protein ◽  
Brown Norway ◽  
Early Event ◽  
Retinyl Ester ◽  
Vitamin A Metabolism ◽  
Ester Hydrolase ◽  
Retinyl Ester Hydrolase ◽  
Plasma Retinol ◽  
The Impact

We examined the alterations in vitamin A metabolism as a result of flupenthixol or cefotiam administration. The impact of these drugs on indices of vitamin A status was evaluated in Brown Norway and Long–Evans rats. Intramuscular drug administration for 28 d resulted in a decline in systemic retinol. Changes in circulating retinol with time for chronic dosing showed drug treatment (P<0·001) and time (P<0·03) to be significant factors, but rat strain (P=0·33) was not a significant factor. Flupenthixol was the most active retinol-lowering compound (P<0·005). At the end of the 28 d period, hepatic retinyl ester hydrolase activity was greater in drug-treated rats than in controls (P<0·05). With regard to effects on liver reserves: (1) flupenthixol treatment resulted in vitamin A depletion (P<0·05); (2) cefotiam treatment stimulated vitamin A accumulation; (3) distinctive patterns of retinol and its esters were seen in response to treatment. It is reasonable to assume that the drugs interfere with vitamin A in at least two ways: (1) lowering of plasma retinol, an early event in the interaction, may be caused by inhibition of hepatic holo-retinol-binding protein secretion or stimulation of clearance, or both; (2) when plasma retinol levels are persistently low, and as the hepatic deposits of the xenobiotics build up, there are changes in the vitamin A pool size and composition of the liver. Candidate enzymes are retinyl ester hydrolase and cytochrome P450. The relationship between these two events will be studied in further detail.

scholarly journals Subsurface swimming and stationary diving are metabolically cheap in adult Pacific walruses (Odobenus rosmarus divergens)

2021 ◽  
Author(s):  
Alicia Borque-Espinosa ◽  
Karyn D. Rode ◽  
Diana Ferrero-Fernández ◽  
Anabel Forte ◽  
Romana Capaccioni-Azzati ◽  
...  
Keyword(s):  
Sea Ice ◽  
Water Surface ◽  
Marine Mammals ◽  
Benthic Habitat ◽  
Metabolic Rates ◽  
Energetic Costs ◽  
Odobenus Rosmarus Divergens ◽  
Odobenus Rosmarus ◽  
Free Ranging ◽  
The Impact

Walruses rely on sea-ice to efficiently forage and rest between diving bouts while maintaining proximity to prime foraging habitat. Recent declines in summer sea ice have resulted in walruses hauling out on land where they have to travel farther to access productive benthic habitat while potentially increasing energetic costs. Despite the need to better understand the impact of sea ice loss on energy expenditure, knowledge about metabolic demands of specific behaviours in walruses is scarce. In the present study, 3 adult female Pacific walruses (Odobenus rosmarus divergens) participated in flow-through respirometry trials to measure metabolic rates while floating inactive at the water surface during a minimum of 5 min, during a 180-second stationary dive, and while swimming horizontally underwater for ∼90 m. Metabolic rates during stationary dives (3.82±0.56 l O2 min−1) were lower than those measured at the water surface (4.64±1.04 l O2 min−1), which did not differ from rates measured during subsurface swimming (4.91±0.77 l O2 min−1). Thus, neither stationary diving nor subsurface swimming resulted in metabolic rates above those exhibited by walruses at the water surface. These results suggest that walruses minimize their energetic investment during underwater behaviours as reported for other marine mammals. Although environmental factors experienced by free-ranging walruses (e.g., winds or currents) likely affect metabolic rates, our results provide important information for understanding how behavioural changes affect energetic costs and can be used to improve bioenergetics models aimed at predicting the metabolic consequences of climate change on walruses.

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