Fate of Biotin
The fate of biotin in the body has been studied by Mistry and co-workers. Rats and chicks were sacrificed one, two, or three hours following an injection of carboxyl-C14-biotin. A maximum of 14 per cent ofthe dose was found in the liver. After fractionation of liver homogenates, 39 to 53 per cent of the activity-there was found in the supernatant, 18 to 29 per cent in the mitochondria, 15 to 23 per cent in nuclear material, and only 2 per cent in the micro somes. It was established that about 90 per cent of the biotin in the cellular fractions of normal rat liver exists in bound forms, except in microsomes, where 80 per cent is, free or as biocytin.
