Technetium metabolism in goats and swine

The intestinal absorption of 99mTc given as pertechnetate (TcO4-) was studied in female goats and swine. In goats given TcO4- orally, only a small fraction of the given radioactivity was found in milk (x = 0.1% of dose) and urine (x = 1.2% of dose). These figures were not substantially changed by pre-treatment with I. Ninety percent was found in feces. In goats injected intraabomasally, secretion of 95mTc into milk increased fivefold and urinary excretion was doubled. In swine administered 95mTc intragastrically, urinary excretion was about 30% of the dose. Swine did not retain the radionuclide in the thyroid gland as long as the goats (T 1/2 20 h in swine versus 30 h in goats). Other organs containing substantial concentrations of Tc 200 h post-administration were livers and kidneys, but in swine the liver contained three times as much 95mTc as the thyroid or kidneys. The conclusion of these experiments would, however, be that the concentrations were insufficient to present a hazard to man from consumption of milk or meat.