Riboflavin Utilization by a Mutant Strain of Single Comb White Leghorn Chickens: 2. Absorption of Radioactive Riboflavin from the Digestive Tract ,

Abstract

INVESTIGATIONS have been reported on certain physiological characteristics of a mutant strain of Single Comb White Leghorn (SCWL) chickens which, on a diet containing sufficient riboflavin, produce eggs deficient in the vitamin (Maw, 1954). One of the outstanding observations is that, in the recessive (rdrd) hen, the free riboflavin concentration of the blood does not increase normally at the onset of egg production (Boucher et al., 1959). It was thought desirable to investigate the possibility that the free vitamin may not be absorbed normally from the digestive tract. If this were true, it could account for the fact that free riboflavin does not accumulate in the blood. METHODS AND MATERIALSRadioactive crystalline riboflavin, 7,8-dimethyl-10(D-ribityl)-isoalloxazine-2-C14, with a specific activity of 1.0 mc./m. mole was obtained from Hoffmann-LaRoche Inc.The method of Coulson and Hughes (1930) was employed for the collection of urine. Radioactivity was determined as counts per minute (cpm.) with…