Abstract
ABSTRACT Three procedures were used to stimulate thyroid function in the golden hamster 1) administration of thyrotrophin (TSH), 2) propylthiouracil (PTU) feeding; and 3) cold exposure. In the three experimental conditions, the composite of functional and morphological responses of the thyroid gland differed. Thyroid glands of TSH and PTU-treated hamsters, but not cold-exposed animals were characterized by marked increase in weight, due predominantly to increase in mass of epithelial cells; follicular epithelial cells of TSH and PTU-treated glands exhibited striking expansion and dilatation of the endoplasmic reticulum and enlargement of the Golgi apparatus. These structural changes were not necessarily concomitants of increased thyroid hormone synthesis, since they were exhibited by glands from PTU-treated animals. Glands of TSH and PTU-treated animals also displayed marked increases in the number of microvilli and apical vesicles. Comparable increases were not seen in cold-exposed animals, even though some functional criteria of activity suggested that these glands were under the influence of TSH. The significance of this is discussed.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
