Effects of hypophysectomy and short- and long-term propylthiouracil treatment on the rat thyroid
Transmission and scanning electron-microscopic studyGaal J.M. · Kovacs K. · Sellers E.A.
Department of Pharmacology, University of Toronto and Department of Pathology, St. Michael’s Hospital, University of Toronto, Toronto, Canada
The follicular architecture of the thyroid gland of the rat following experimentally induced states of hypo- and hyperactivity was investigated by scanning electron microscopy and the findings correlated with both light and transmission electron-microscopic observations. By scanning electron microscopy, the microvilli on the apical surfaces of the follicular cells showed the most striking changes; following hypophysectomy, the cells were flattened and the microvilli had decreased in both size and number, whereas following propylthiouracil (PTU) administration the epithelial cells were enlarged, and marked hyperplasia and hypertrophy of the microvilli was present. Of particular interest is that the changes observed following PTU appeared to be identical in short- and long-term PTU-treated rats. Similarly, the heterogeneity of the follicular cells observed within the follicles was maintained under the various experimental conditions. Although the functional significance of these observations is not quite clear, it appears justifiable to assume that a reduction of luminal surface area of the follicular epithelial cell may hinder, whereas an increase may facilitate transport process across the apical cell membrane.
© 1976 S. Karger AG, Basel
J.M. Gaal, Department of Pharmacology, University of Toronto, Toronto, Ont. M5S1A8 (Canada)
Received: September 1, 1975
Published online: July 09, 2008
Number of Print Pages : 10
Cells Tissues Organs (in vivo, in vitro)
Vol. 96, No. 3, Year 1976 (Cover Date: 1976)
Journal Editor: Denker H.-W. (Essen), English A.W. (Atlanta, Ga.)
ISSN: 1422–6405 (Print), eISSN: 1422–6421 (Online)
For additional information: http://www.karger.com/CTO