help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Rapoport, B.
Right arrow Articles by Rose, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Rapoport, B.
Right arrow Articles by Rose, M.

Endocrinology, Vol 100, 755-764, Copyright © 1977 by Endocrine Society

ARTICLES

Cultured thyroid cell adenosine 3',5'-cyclic monophosphate response to thyrotropin: loss and restoration of sensitivity to iodide inhibition

B Rapoport, RJ Adams and M Rose
Medical Service, Veterans Administration Hospital, San Francisco, California 94121.

Unlike in all other thyroid preparations, exposure of dog thyroid cells in long-term monolayer culture to iodide (10(-7) to 10(-3) M for up to 19 h did not blunt the subsequent adenosine 3', 5'-cyclic monophosphate (cAMP) response to thyrotropin (TSH) stimulation. This lack of effect of iodide was observed even when confluent thyroid cells were "follicularized" by the action of TSH in the culture medium. Preincubation of these cells in thyroxine (T4) and triiodothyronine (T3) was similarly without effect on the subsequent cAMP response to TSH. Study of thyroid cells during the early phase of primary culture demonstrated that inhibition by iodide (10(-4) M) of the cAMP response to TSH occurred after 7 h but was lost after 48 h of cell culture. This inhibitory effect of iodide was prevented by the inclusion of methimazole in the preincubation medium. As with iodide-insensitive cells, T4 and T3 were without effect on the cAMP response to TSH in iodide-sensitive thyroid cells. Exposure of iodide-insensitive thyroid cells to iodide-containing medium obtained after 2 h of incubation with dog thyroid slices, as well as to medium enriched with the 100,000 g supernatant fraction of homogenates prepared from these thyroid slices, did not restore the inhibitory action of iodide. However, iodide- sensitivity of the cAMP response to TSH was restored by preincubation of iodide-insensitive cells in 10(-4) M iodide plus an H2O2-generating system (glucose-glucose oxidase). These data suggest that T4 and T3 are not organic iodine inhibitors of the thyroid cAMP response to TSH. In addition, they provide evidence against the existence of a soluble, freely diffusible, organic iodine inhibitor of thyroid adenylate cyclase. The loss of sensitivity to iodide inhibition of adenylate cyclase that occurs in thyroid cells shortly after initiation of primary culture appears to be related to a defect in the cellular organification mechanism, possibly the H2O2-generating system.


This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
V. Panneels, P. Macours, H. V. d. Bergen, J.-C. Braekman, J. Van Sande, and J.-M. Boeynaems
Biosynthesis and Metabolism of 2-Iodohexadecanal in Cultured Dog Thyroid Cells
J. Biol. Chem., September 20, 1996; 271(38): 23006 - 23014.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1977 by The Endocrine Society