EFFECT OF STORAGE OF NAI131SOLUTIONS UPON THE THYROID UPTAKE BY DAY-OLD CHICKS1

Abstract

Several microcuries of two to three week old solutions of NaI¹³¹ were spotted on sheets of filter paper and developed one dimensionally in an ascending technique using n-Butanol saturated with 3N NH4OH. After 20 hours, the papers were air-dried and radioautographed. The “extraneous band,” which moves slightly faster than the NaI¹³¹ band, was cut out, eluted with 50% alcohol and concentrated to 5 microcuries⁄ml. Studies were conducted on the factors affecting the thyroid uptake of fresh NaI¹³¹ solution and of the extraneous band solution by day-old chicks. At all the dosage levels (0.1, 0.5, 1.0 microcurie) tested, the thyroid uptake of the extraneous band solution was significantly lower than that of fresh NaI¹³¹ solution. Administration of iodine (NaI¹²⁷) either orally in the diet or by injection, lowers the uptake of fresh NaI¹³¹ solution. However, the thyroid uptake of the extraneous band solution is enhanced by simultaneous injection of 2 to 5 µg. of NaI¹²⁷