Endocrinology, Vol 100, 346-350, Copyright © 1977 by Endocrine Society
Thyrotropin stimulation of 32P incorporation into the phospholipids of canine thyroid adenocarcinoma
PB Schneider and I Leav
Six carcinomas of the canine thyroid were studied. Five of the six tumors
were functional on 131I scan and caused hyperthyroidism in two cases. The
tumors were all of predominantly compact cellular histology with rare to
moderate numbers of microfollicles. After surgical removal tumor slices
were incubated with 32P in Krebs-Ringer-tris buffer with or without 0.1
U/ml of bovine TSH, and the specific activity of the extracted
phospholipids was measured. TSH stimulated phosphatide turnover clearly in
5 cases and probably also in the 6th. Analysis of fractionated
phospholipids in 2 cases showed that the response to TSH was mainly in the
phosphatidic acid and phosphatidylinositol. These studies show that a
malignant tumor may still retain at least one complete control system
extending from TSH receptors to the final metabolic response.
