Adenylate cyclase activity in thyroid tissue from patients with untreated Graves' disease.

Abstract

Both basal and TSH-stimulated (10 mU/ml) adenylate cyclase (AC) activities were measured in a crude plasma membrane function (800–10,000 × g) prepared from 3–10 mg (wet wt) thyroid tissue, which was obtained from patients with Graves disease and thyroid adenoma and from normal subjects. Twelve thyroid tissues of patients with untreated Graves disease and 4 adenoma tissues were obtained by needle biopsy, while 15 normal thyroid tissues, 20 tissues of patients with Graves disease under treatment, and 8 adenoma tissues were obtained at the time of operation. AC activities measured in 4 thyroid adenoma tissues obtained by needle biopsy did not differ significantly from those in 8 adenoma tissues obtained at the time of operation. In normal thyroid tissue the basal AC activity and the percent stimulation by TSH were 1.25 ± 0.46 (mean ± SD) pmol cAMP generated/mg wet wt-10 min and 134.0 ± 23.8%, respectively. In untreated Graves thyroid tissue, the mean basal AC activity (2.76 ± 0.57) was significantly high...