Absorption and Retention in Sheep of Technetium Administered into the Rumen as Pertechnetate or Bound to Food

Abstract

Technetium is produced with high yields of about 6% at nuclear fission and has been released during nuclear weapons testing. Technetium-99m is used in increasing quantities in nuclear medicine. Due to its long half- life of 210,000 years Tc-99 accumulates in the environment and undergoes a variety of chemical and biological transformations which could profoundly modify its absorption by the intestine and its metabolism in animals. Moreover, the age, sex and iodine content of the diet may markedly influence the fate of technetium. Information on technetium metabolism in large animals, particularly in ruminants, is scanty; we have therefore studied in sheep, in parallel with similar investigations in rats, uptake, distribution and excretion of Tc-99 labelled with Tc-95m given into the rumen as pertechnetate or bound to algae. These investigations complement earlier ones where Tc-95m was given by the intravenous route.