Abstract
Adrenals of the hamster, the mouse and the rat were studied.
Radioactive iodate solution was prepared by mixing carrier-free I131 with a saturated solution of potassium iodate. In adrenals immersed in this solution for 3-96 hours and subsequently fixed in 10 per cent formalin, a typical brown reaction was seen in some, presumably noradrenaline-containing, cells of the medulla. Radioautographs prepared of the same sections indicated that the distribution of the brown color and that of the radioactivity were identical. This suggests that the brown color produced by treatment with iodate is due to an iodine-containing compound. The cortex exhibited only a weak radioactivity and no color.
Adrenals immersed in a mixture of 1 volume of commercial formalin and 9 volumes of the radioactive iodate solution for 12-96 hours showed a brown color in all medullary cells. The medulla was demonstrated by radioautographs to contain large quantities of iodine. However, the cortex was also strongly radioactive in spite of previous treatment with an alcohol-ether mixture.
Some observations on the chromaffin reaction were also reported.