The ultrastructure of rat thyroid glands under experimental conditions in organ culture

A technique has been described which permits the maintenance for up to 6 days in organ culture of explanted thyroid glands. This provided a suitable model for an electron microscope study to be carried out on glands under experimental conditions. The appearance of the control gland was consistent with stimulation by TSH. The formation of 'intracytoplasmic' follicles was caused by injection of TSH into the culture. Parafollicular (light) cells were described for the first time in organ cultured thyroid glands.