Biomaterial Database

Effects of long-acting thyroid stimulator on thyrotropin stimulation of adenyl cyclase activity in thyroid plasma membranes. 1972

K Yamashita, and J B Field

Both thyroid-stimulating hormone (TSH) and long-acting thyroid stimulator (LATS) stimulated adenyl cyclase activity in plasma membranes obtained from bovine thyroid glands. The stimulation induced by LATS was much less than that obtained with maximal amounts of TSH. LATS inhibited TSH stimulation of adenyl cyclase activity while an equivalent amount of normal human gamma-globulin did not influence basal or TSH-stimulated activity. The inhibition by LATS appeared to be noncompetitive and was greatest when the plasma membranes were initially exposed to LATS for 30 min at 0 degrees C before being incubated with TSH for 10 min at 37 degrees C. Inhibition could still be demonstrated when the plasma membranes were incubated for 30 min at 0 degrees C with TSH before the addition of LATS. Prolonging the period of incubation of plasma membranes with LATS from 30 to 60 min did not augment the stimulation of adenyl cyclase or increase the inhibition of the effect of TSH. Papain digests of LATS also increased adenyl cyclase activity of thyroid plasma membrane and inhibited the stimulation induced by TSH. The inhibitory effect of LATS was not completely specific for TSH and thyroid plasma membranes since glucagon stimulation of adenyl cyclase in hepatic plasma membranes was also inhibited, but to a lesser extent. In contrast to the results obtained with thyroid plasma membranes, LATS did not influence basal adenyl cyclase activity in hepatic plasma membranes. Furthermore equivalent amounts of normal human gamma-globulin also decreased glucagon stimulation of adenyl cyclase activity in plasma membranes obtained from liver. The present data suggest that LATS stimulation of adenyl cyclase in thyroid plasma membranes might be due to a change in the membrane configuration rather than binding to a specific receptor site. Such modification of the membrane structure could interfere with the binding of TSH to specific receptors or to the subsequent stimulation of adenyl cyclase. However, the results do not exclude the possibility that some component in the preparation other than LATS might be responsible for the inhibition of the stimulation by TSH.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008135	Long-Acting Thyroid Stimulator	An immunoglobulin G, often found in the blood of hyperthyroid individuals. It stimulates the thyroid for a longer duration than does thyrotoxin and may cause hyperthyroidism in newborns due to placental transmission.	LATS,Thyroid Stimulating Hormone Receptor Autoantibodies,Thyroid Stimulating Hormone Receptor Autoantibody,Thyroid Stimulator, Long-Acting,Thyrotropin Receptor Antibodies,Thyrotropin Receptor Antibody,Thyrotropin Receptor Autoantibodies,Thyrotropin Receptor Autoantibody,Antibody, Thyrotropin Receptor,Autoantibody, Thyrotropin Receptor,Long Acting Thyroid Stimulator,Receptor Antibody, Thyrotropin,Receptor Autoantibody, Thyrotropin,Thyroid Stimulator, Long Acting
D010206	Papain	A proteolytic enzyme obtained from Carica papaya. It is also the name used for a purified mixture of papain and CHYMOPAPAIN that is used as a topical enzymatic debriding agent. EC 3.4.22.2.	Tromasin
D002247	Carbon Isotopes	Stable carbon atoms that have the same atomic number as the element carbon but differ in atomic weight. C-13 is a stable carbon isotope.	Carbon Isotope,Isotope, Carbon,Isotopes, Carbon
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D002474	Cell-Free System	A fractionated cell extract that maintains a biological function. A subcellular fraction isolated by ultracentrifugation or other separation techniques must first be isolated so that a process can be studied free from all of the complex side reactions that occur in a cell. The cell-free system is therefore widely used in cell biology. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p166)	Cellfree System,Cell Free System,Cell-Free Systems,Cellfree Systems,System, Cell-Free,System, Cellfree,Systems, Cell-Free,Systems, Cellfree
D003080	Cold Temperature	An absence of warmth or heat or a temperature notably below an accustomed norm.	Cold,Cold Temperatures,Temperature, Cold,Temperatures, Cold
D005719	gamma-Globulins	Serum globulins that migrate to the gamma region (most positively charged) upon ELECTROPHORESIS. At one time, gamma-globulins came to be used as a synonym for immunoglobulins since most immunoglobulins are gamma globulins and conversely most gamma globulins are immunoglobulins. But since some immunoglobulins exhibit an alpha or beta electrophoretic mobility, that usage is in decline.	gamma-Globulin,gamma Globulin,gamma Globulins
D005934	Glucagon	A 29-amino acid pancreatic peptide derived from proglucagon which is also the precursor of intestinal GLUCAGON-LIKE PEPTIDES. Glucagon is secreted by PANCREATIC ALPHA CELLS and plays an important role in regulation of BLOOD GLUCOSE concentration, ketone metabolism, and several other biochemical and physiological processes. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1511)	Glucagon (1-29),Glukagon,HG-Factor,Hyperglycemic-Glycogenolytic Factor,Proglucagon (33-61),HG Factor,Hyperglycemic Glycogenolytic Factor