The liver but not the skin is the site for conversion of a red carotenoid in a passerine bird

Carotenoids may provide numerous health bene- fits and are also responsible for the integumentary colora- tion of many bird species. Despite their importance, many aspects of their metabolism are still poorly known, and even basic issues such as the anatomical sites of conversion remain controversia...

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Bibliographic Details
Authors: Val, Esther del, Senar, Juan Carlos, Garrido Fernández, J., Jarén-Galán, Manuel, Borràs, Antoni, Cabrera, Josep, Negro, Juan J.
Format: article
Publication Date:2009
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/38927
Online Access:http://hdl.handle.net/10261/38927
Access Level:Open access
Keyword:Carotenoid conversion
Feather pigments
Follicles
Liver
Loxia curvirostra
Description
Summary:Carotenoids may provide numerous health bene- fits and are also responsible for the integumentary colora- tion of many bird species. Despite their importance, many aspects of their metabolism are still poorly known, and even basic issues such as the anatomical sites of conversion remain controversial. Recent studies suggest that the transformation of carotenoid pigments takes place directly in the follicles during feather growth, even though the liver has been previously recognised as a storing organ for these pigments with a certain potential for conversion. In this context, we analysed the carotenoid profile of plasma, liver, skin and feathers of male Common Crossbills (Loxia curvirostra). Interestingly, the derivative feather pigment 3-hydroxy-echinenone was detected in the liver and in the bloodstream (i.e. the necessary vehicle to transport metab- olites to colourful peripheral tissues). Our results demon- strate for the first time with empirical data that the liver may act as the main site for the synthesis of integumentary carotenoids. This finding contradicts previous assumptions and raises the question of possible inter-specific differences in the site of carotenoid conversion in birds.