The receptor for thyrotropin-releasing hormone has been located in the plasma membranes of bovine anterior pituitary gland. Treatment of membranes with phospholipase A, phospholipase C, or digitonin or addition of lysophosphatidylcholine diminishes or completely destroys the ability of membranes to bind 3H-labeled thyrotropin-releasing hormone. Phospholipase D was without effect. These reductio...

Sensitive immunologic techniques and more purified preparations of bovine pituitary thyrotropin have made it possible to re-examine the question of whether thyrotropin acts as an antigen upon injection into heterologous species. This possibility was first indicated by Werner (1, 2) in 1936, to explain the loss of responsiveness to thyrotropin which Collip and Anderson (3) previously had observe...

Retro-orbital tissue membranes have been shown to have adenylate cyclase activity which can be stimulated by thyrotropin and by an exophthalmogenic factor derived from the thyrotropin molecule by partial pepsin digestion. This stimulable activity is maximal after 15 min and is optimal in the presence of 3 mM magnesium and 1.5 mM ATP. Calcium salts are exquisitely inhibitory to the hormonal stim...

BACKGROUND One night of sleep deprivation induces a brief remission in about half of depressed patients. Subclinical hypothyroidism may be associated with depression, and changes in hypothalamic-pituitary-thyroid function may affect the mood response to sleep deprivation. We wished to define precisely the status of the hypothalamic-pituitary-thyroid axis of depressed patients during sleep depri...

Serially cultivated thyroid follicular cells are not active in hormone synthesis but retain a thyrotropin-responsive adenylate cyclase. The exposure of such cells to thyrotropin leads to an increase in the concentration of intracellular cAMP and a drastic change in morphology including a total cytoplasmic arborization. The present communication describes these changes at the cytoskeletal level ...

A double-blind crossover trial was conducted of thyrotropin releasing hormone treatment in six patients with amyotrophic lateral sclerosis. Patients received 4 mg of thyrotropin releasing hormone intramuscularly daily during the two-week treatment period. Although three patients reported subjective improvement, objective evaluation failed to demonstrate therapeutic effectiveness of thyrotropin ...

There is a need for improvement of thyrotropin measurements in the clinical laboratory, specifically in the lower portion of the normal range. We cite realistic examples of incorrect, misleading data generated with many thyrotropin kits currently in use and propose a practical laboratory protocol to evaluate the performance of a procedure for determining thyrotropin. The protocol integrates med...

We compared the utility of a sensitive immunoradiometric assay for serum thyrotropin as a "first-line" thyroid-function test with a strategy based on first measuring total thyroxin in serum. The immunoradiometric assay appears to distinguish primary hypothyroidism and hyperthyroidism from euthyroidism in "new" patients. The role of this test in monitoring antithyroid treatment or thyroxin-repla...

Thyrotropin stimulates the incorporation of 32P into phospholipids of thyroid slices incubated with 32P04. To determine whether this effect could be secondary merely to an increase in the specific activity of the terminal (y) P of ATP, a precursor of phospholipid P, the effect of thyrotropin on calf thyroid slice ATP was measured with an assay which is selective for ATP-T-~~P specific activity....

Pituitary thyrotropin excess resulting in hyperthyroidism has been previously reported in only 25 patients, of whom 19 had a pituitary tumour. This report describes a patient in whom a thyrotropin-producing pituitary tumour was associated with triiodothyronine thyrotoxicosis. Hypophysectomy was followed by a prompt fall in serum thyrotropin and a return to a euthyroid state.