Activation of Thyroid Adenyl Cyclase by Antisera to Thyroid Plasma Membrane Preparations

Abstract

Adenyl cyclase was assayed in a series of plasma membrane fractions prepared from bovine thyroids using sucrose density gradient ultracentrifugation. The activity of adenyl cyclase in the plasma membranes was stimulated several-fold by antisera raised in rabbits against the plasma membranes and by purified IgG [immunoglobulin] prepared from these antisera. The antibodies to thyroid plasma membrane manifest properties similar to those of the Ig long-acting thyroid stimulator (LATS) and human specific thyroid-stimulating Ig (HTSI) found in patients with Graves'' disease. In these patients, the antigen which leads to the production of LATS and HTSI is most likely situated in the thyroid plasma membrane.