title: The site of 7-dehydrocholesterol ultraviolet photolysis in domestic fowls.
abstract: The site of the photolytic reaction leading to Vitamin D3 in fowls integument has been investigated by histochemical and biochemical analysis. The Vitamin D3 precursor, 7-dehydrocholesterol, is synthetized and stored mainly in the uropygial gland and in the same localization several amount of Vitamin D3 may be biochemically detected. 7-dehydrocholesterol and Vitamin D3 are also present although in a lesser amount in the unfeathered skin of the legs. Photolytic conversion of the Vitamin D3 precursor of uropygial origin may occur also on the dorsal feathers.
mesh_terms: D000818:Animals; D001415:Back; D002645:Chickens / Q000378:metabolism*; D002762:Cholecalciferol / Q000032:analysis; D002775:Cholestadienols / Q000378:metabolism*; D003684:Dehydrocholesterols / Q000378:metabolism*; D005241:Feathers / Q000378:metabolism; D006614:Hindlimb; D006651:Histocytochemistry; D010782:Photolysis; D012627:Sebaceous Glands / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D002775:Cholestadienols; D003684:Dehydrocholesterols; D002762:Cholecalciferol; C016705:7-dehydrocholesterol