Administration of 131I to produce an athyroid model animal

In male Wistar rats weighing 90-500 g 131I thyroidectomy was safely carried out by i.p. application of twice a dose of 18.5 MBq with an interval of 7 days and of 37.0 MBq once, resp., with the latter to prefer because of the reason of radiation hygiene. The success of the painless technique was controlled by in vivo and in vitro methods, such as determination of body mass, rectal temperature measurement, estimation of 131I accumulation in extirpated tracheal rings, and histological examination of the tracheal region