Effect of Digestive Enzymes on Bound Vitamin B₁₂¹

Immunologic Studies of Intrinsic Factor

“…The fresh tissues were homogenized in saline using a glass homogenizer. After centrifugation the B,,-binding capacity of the supernatant was estimated by a dialysis technique (18). Radioactive vitamin B,, was added in a slight excess, according to the binding capacity.…”

Body Distribution, Turnover Rate, and Radiation Dose after the Parenteral Administration of Radiovitamin B121

“…Such attempts have been madc previously (1 7, 18) and suggest a daily requirement of the magnitude of 7 pg. However, this figure is higher than that olxained by studying the excretion of non-lalxled R,, (40). The difference may be duc to a n excretion of radioactive but niicrobiologically inactive compounds or to a more rapid rate of turnover of injected than of absorbed vitamin BIZ.…”

“…The rooster and the pig were kept on ordinary cornmcrcial diets, whereas the calf was given only milk in an attempt to keep the diet poor in cobalt. extracts from some tissues was assayed activity, but no measurable activity using Lactobacillus leichmaiinii 313 ATCC could be found in subcutaneou: fat or 7830 as previously described (40). erythrocytes (3, 42).…”