Activation of membrane-bound adenylcyclase by thyroid stimulating antibodies

Abstract

Human thyroid plasma membranes isolated from thyroids from patients with Graves'' disease or non-toxic nodular goiters produced, under basal conditions, .apprx. 100 pmol cAMP/mg membrane protein in 30 min at 37.degree. C. TSH [thyrotropin] increased the membrane response from a Graves'' thyroid by up to 11-fold. cAMP production with Ig from patients with Graves'' disease was 4 times that from normal Ig. The onset of action of thyroid stimulating antibodies (TSAb) was rapid and persisted for 30 min of incubation. A change of incubation buffer from 20 mM to 200 mM Tris-HCl reduced the degree and altered the pattern of Ig stimulation; maximal TSH stimulation was unchanged. The in vitro interaction between the TSH receptor system and TSAb or TSH will differ according to the conditions used.