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The effects of dietary carotenoid intake on carotenoid accumulation in the retina of a wild bird, the house finch (Carpodacus mexicanus)
- Source :
- Archives of biochemistry and biophysics. 504(1)
- Publication Year :
- 2010
-
Abstract
- Carotenoid pigments accumulate in the retinas of many animals, including humans, where they play an important role in visual health and performance. Recently, birds have emerged as a model system for studying the mechanisms and functions of carotenoid accumulation in the retina. However, these studies have been limited to a small number of domesticated species, and the effects of dietary carotenoid access on retinal carotenoid accumulation have not been investigated in any wild animal species. The purpose of our studies was to examine how variation in dietary carotenoid types and levels affect retinal accumulation in house finches ( Carpodacus mexicanus ), a common and colorful North American songbird. We carried out three 8-week studies with wild-caught captive birds: (1) we tracked the rate of retinal carotenoid depletion, compared to other body tissues, on a very low-carotenoid diet, (2) we supplemented birds with two common dietary carotenoids (lutein + zeaxanthin) and measured the effect on retinal accumulation, and (3) we separately supplemented birds with high levels of zeaxanthin – an important dietary precursor for retinal carotenoids – or astaxanthin – a dominant retinal carotenoid not commonly found in the diet (i.e. a metabolic derivative). We found that carotenoids depleted slowly from the retina compared to other tissues, with a significant (∼50%) decline observed only after 8 weeks on a very low-carotenoid diet. Supplementation with lutein + zeaxanthin or zeaxanthin alone significantly increased only retinal galloxanthin and e-carotene levels, while other carotenoid types in the retina remained unaffected. Concentrations of retinal astaxanthin were unaffected by direct dietary supplementation with astaxanthin. These results suggest highly specific mechanisms of retinal carotenoid metabolism and accumulation, as well as differential rates of turnover among retinal carotenoid types, all of which have important implications for visual health maintenance and interventions.
- Subjects :
- Male
Time Factors
Biophysics
Zoology
macromolecular substances
Biochemistry
Retina
chemistry.chemical_compound
Pigment
Astaxanthin
Botany
polycyclic compounds
medicine
Animals
Passeriformes
Carpodacus mexicanus
Molecular Biology
Carotenoid
chemistry.chemical_classification
biology
Dose-Response Relationship, Drug
organic chemicals
food and beverages
Retinal
biology.organism_classification
Carotenoids
biological factors
Songbird
Diet
Zeaxanthin
medicine.anatomical_structure
chemistry
visual_art
Dietary Supplements
visual_art.visual_art_medium
Housing
Female
Subjects
Details
- ISSN :
- 10960384
- Volume :
- 504
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Archives of biochemistry and biophysics
- Accession number :
- edsair.doi.dedup.....57473b446ee77809665fe0a1cf96a130