title: Insensitivity of dogs to the effects of nonspecific bound vitamin A in plasma.
abstract: Retinol bound to its specific carrier, the retinol-binding protein, is known to be the physiological way vitamin A is transported in blood. Unspecific, lipoprotein-bound vitamin A has so far only be reported under the condition of hypervitaminosis A. In this investigation vitamin A concentrations in dog plasma are reported (2300 ng/ml), showing for the first time a species which, under physiological conditions, transports most of its vitamin A in plasma as retinyl esters (70%) associated with lipoproteins. This phenomenon might indicate that dogs are less sensitive to the effects of nonspecific delivery of vitamin A than other species. This can open new aspects in retinoid research, especially with regard to hypervitaminosis A - an undesirable side effect of the beneficial use of retinoids in dermatology and oncology.
authors.affiliation: Institute of Physiology, Physiological Chemistry and Nutrition Physiology, Veterinary Faculty, Ludwig-Maximilians-University, München, West Germany.
authors.forename: F J
authors.initials: FJ
authors.lastname: Schweigert
mesh_terms: D000818:Animals; D004285:Dogs; D005260:Female; D008297:Male; D012177:Retinol-Binding Proteins / Q000378:metabolism; D054839:Retinol-Binding Proteins, Plasma; D013045:Species Specificity; D014801:Vitamin A / Q000097:blood* / Q000633:toxicity
chemical_list: D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D014801:Vitamin A