Showing papers by "Charles Rosenblum published in 1963"

Tissue distribution and storage forms of vitamin B12 injected and orally administered to the dog.

Abstract: Summary1. The distribution of oral and intravenous Vit. B12 was determined simultaneously in dogs using vitamin preparations labeled respectively with cobalt-57 and cobalt-60. 2. Thirty-one days after administration, the ratio of Co57/Co60 was constant in all tissues, indicating the existence of a common pool for cobalamin and related compounds regardless of mode of administration. 3. Conversion of administered labeled Vit. B12 to a noncyano form was demonstrated by reverse isotope dilution analysis of livers. This is true regardless of mode of administration. 4. It is suggested that chemical changes in the vitamin account in part for the complex excretion pattern of labeled Vit. B12.

Experiences with tritiated compounds prepared by exposure to tritium gas.

Abstract: The Random Tritiation of organic compounds by contact with curie quantities of tritium gas [1] has greatly simplified the labeling of many organic compounds. Despite the absence of an adequate theory for predicting the specific activity attainable with a particular substance, the method has proven successful in labeling a great variety of compounds, including biologically active materials such as ribonucleic acid, lysozyme [2], and insulin [3]. In the Merck Sharp & Dohme Research Laboratories, this technique has been employed for the tritium labeling of a steroid, many substituted aromatic compounds, a partly saturated polycyclic structure, a poly-basic amino acid, a porphyrin-like structure, a sugar phosphate, and, in confirmation of an earlier report, [1] sucrose. Conditions prevailing during the tritiation of these compounds, as well as specific activities attained, are listed in Table I.