Development of fetal rat thyroid with special reference to uptake of radioactive iodine

✍ Scribed by Carpenter, Esther

• Publisher: John Wiley and Sons
• Year: 1959
• Tongue: English
• Weight: 442 KB
• Volume: 142
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1401420112

✦ Synopsis

FIVE FIGURES

IKTRODUCTION

I n the fetal rat thyroid colloid formation and folliculation take place very rapidly during the last few days before birth (Kull, '26 ; Sugiyama, '41). Using Mallory 's triple stain, Hall and Kaan ('42) reported colloid and primitive follicular arrangement in the gland at the end of the 16th day of gestation and were able to demonstrate physiological activity of the 18-day fetal thyroid by the tadpole test. Using the periodic acid-Schiff reaction (MeManus, '48) on a still larger number of embryonic glands, Carpenter and Rondon-Tarchetti ( ' 5 7 ) found small colloid droplets in less than half of those removed from 16-day embryos, but small droplets were common throughout the sections of glands from 17-day embryos. The magenta color of the colloid obtained with the PAS method was much easier to detect than the pale blue of the Mallory's stain in sections of glands of the same age.

Soon after radioactive iodine became available for biological use, Gorbman and Evans ('43) were able to demonstrate its incorporation in the colloid of the 18-19 day fetal rat thyroid by making autoradiographs of sections of the gland.

I n their experiments pregnant females were injected subcutaneously with 35 microcuries of the isotope two days before