The Detection of Intestinal Absorption of Co57 Tagged Vitamin B12 by Serum Counting

doi:10.1059/0003-4819-62-1-97

The Detection of Intestinal Absorption of Co⁵⁷ Tagged Vitamin B₁₂ by Serum Counting

PAUL R. MCCURDY, M.D.

Requests for reprints should be addressed to Paul R. McCurdy, M.D., Government of the District of Columbia, D. C. General Hospital,
19th Street and Massachusetts Ave., Washington, D. C. 20003
.

Excerpt

The usual cause for vitamin B₁₂ deficiency is its specific malabsorption caused by lack of gastrict intrinsic factor. Nonsurgical deficiency of intrinsic factor is pernicious anemia. The Schilling test was devised to measure gastrointestinal absorption of vitamin B₁₂ (1). In it is measured the radioactivity flushed out in the urine during the 24 hours after the oral administration of B₁₂ tagged with a radioactive isotope of cobalt. To differentiate true Addisonian pernicious anemia from other causes of failure to absorb vitamin B₁₂ unrelated to the secretion of gastric intrinsic factor, one should repeat an abnormal Schilling test and give a

Acknowledgments

We are grateful to Dr. Elmer Alpert of Merck Sharp & Dohme Research Laboratories, West Point, Pa., for a generous supply of Co⁵⁷ B₁₂, and to Dr. Leon Ellenbogen of Lederle Laboratories, Pearl River, N. Y., for a generous supply of intrinsic factor.

The technical assistance of Miss Mona M. Gieschen and Mrs. Annemarie Wojtal, along with the secretarial assistance of Mrs. Geneva Curry, are gratefully acknowledged in the preparation of this manuscript.

Summario in Interlingua

Esseva investigate un modificate test pro le absorption gastrointestinal de vitamina B-12. Inter 8 e 12 horas post le administration oral de 0,5 µg de cyanocobalamina marcate con 0,5 µc de Co-57, un specimen de sero es obtenite, e 4 ml de illo es contate in un puteiforme contator scintillatori equipate con un analysator de radiation a canal unic e un automatic excambiator de specimen. Le test pote esser executate in simultaneitate con un test del excretion urinari de Schilling o illo pote esser executate sol sin collection de urina. Dece-tres patientes con anemia perniciose de Addison habeva minus que 8 cpm per 4 ml de sero 8 a 12 horas post le administration de radiocobalamina. Un habeva 12 cpm per 4 ml. Quaranta-quatro patientes con normal absorption de vitamina B-12 habeva 15 cpm o plus per 4 ml e usualmente plus que 20. Morbo renal non produceva false resultatos. Patientes con malabsorption de vitamina B-12 non-addisionian habeva basse contatationes seral, sed in illes nulle augmento del contatation occurreva quando le test esseva repetite con factor intrinsec, como il esseva le caso in ver anemia perniciose. Le contation in sero, 8 a 12 horas post un dose oral de vitamina B-12 a Co-57, permitte un differentiation inter normal e reducite absorption de vitamina B-12 tanto preste como le test standard del excretion urinari. Le test a base del sero evita errores causate per morbo renal e inadequatias in le collection de urina. Illo etiam permitte le mesuration del absorption de vitamina B-12 sin le administration de un grande dose parenteral de vitamina B-12.

Article and Author Information

From the Georgetown Medical Division, District of Columbia General Hospital, Washington, D. C., and the Department of Medicine, Georgetown University School of Medicine, Washington, D. C.
This work was supported in part by a grant AM 02823 from the National Institute of Arthritis and Metabolic Disease, National Institutes of Health, U. S. Public Service, Bethesda, Md.
- Received July 13, 1964.
- Accepted September 23, 1964.