Glucose dependence of thyrotropin-stimulated thyroid hormone formation.

TSH (100 mU/ml) stimulation of organic binding of iodide, including formation of T4, in bovine thyroid slices was 3-fold greater when the incubation medium contained glucose; this effect of glucose was apparent at 0.1 mM and was maximal at 1 mM. TSH at 5 mU/ml enhanced organisation of iodide in calf thyroid slices only with the presence of glucose in the medium. These effects of glucose are not mediated by mechanisms involving iodide transport. TSH stimulation of O2 consumption of slices was also significantly greater in glucose-enriched medium. Glucose was also required for maximal increase of iodide organisation in response to dibutyryl cAMP and prostaglandin E1 in canine thyroid slices. Glucose did not affect the TSH-stimulated increase in the cAMP content of calf thyroid slices. Galactose, fructose, or pyruvate could replace glucose in supporting TSH stimulation of organic binding; TSH increased oxidation of [1-14C]galactose, [U-14C]fructose, or [3-MC]pyruvate, as well as that of [1-14C]glucose. In th...