title: Plasma vitamin A composition and retinol-binding protein concentration during egg formation in laying hens.
abstract: Blood plasma vitamin A composition (retinol, retinyl ester) and retinol-binding protein (RBP) were determined in three phases (empty; soft- and hard egg) of the egg formation period in laying hens. The retinyl ester level remained in the range of 6 to 11% of the total plasma vitamin A concentration during egg formation. The retinol and RBP increased significantly during the time of soft period. The molar ratio between retinol and RBP ranged between 0.72-0.77. The increase of retinol and RBP may be caused by the sexual steroid effect for satisfying the retinoid needs of the ovarium and shell gland (avian uterus).
authors.affiliation: Department of Animal Physiology and Hygiene, University of Agricultural Sciences, Gödöllö, Hungary.
authors.forename: L
authors.initials: L
authors.lastname: Bárdos
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000378:metabolism*; D005260:Female; D010058:Oviposition; D010063:Ovum / Q000502:physiology*; D012177:Retinol-Binding Proteins / Q000378:metabolism*; D054839:Retinol-Binding Proteins, Plasma; D014801:Vitamin A / Q000097:blood*
chemical_list: D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D014801:Vitamin A