Abstract
Long-term treatment of rats with theophylline induces the formation of a goiter. The effect of theophylline depends both on the length of treatment and on the dose administered but is independent on the diet. The morphological aspect of the gland is typical of hyperfunctioning state as demonstrated also by the significant increase of those parameters known to be early stimulated by TSH, such as glucose oxidation, phospholipid and RNA synthesis. At the doses used, theophylline is not an antithyroid agent and the goiter which it produces is not related to an increase in the renal excretion of iodides due to the diuretic effect of such drug. The thyroid in theophylline-treated animals is unresponsive to the in vitro addition of TSH. Adenyl-cyclase activity in such glands is significantly stimulated while phosphodiesterase activity is only slightly inhibited. A significant increase of all measured parameters of the gland, including that of the adenyl-cyclase activity, the lack of TSH stimulation in vitro, besides the slight inhibition of the phosphodiesterase activity, suggest that the theophylline-induced goiter is related to an increased pituitary release of TSH.
Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
