Biomaterial Database

Calcium-dependent release of carboxyl-terminal fragments of parathyroid hormone by hyperplastic human parathyroid tissue in vitro. 1986

D A Hanley, and L M Ayer

The role of intracellular calcium in the secretion of fragments of PTH by human parathyroid tissue has not been examined previously. We used an in vitro perifusion system to study this phenomenon. Hyperplastic human parathyroid tissue, obtained at surgery from patients with chronic renal failure, was sliced into small pieces, placed in perifusion chambers, and exposed to low (0.5 mM) or high (2.0 mM) calcium concentrations. PTH secreted into the perifusion medium was analyzed by gel exclusion chromatography and RIA using a carboxyl-terminal antiserum. Under high calcium conditions, proportionally more carboxyl-terminal fragments of PTH (65.3%) were released by the perifused tissue than intact PTH (34.7%). When perifused with low calcium medium, the tissue released more intact PTH (55.0%) than carboxyl-terminal fragments (45.0%). These studies are consistent with the suggestion that calcium-dependent intracellular degradation of PTH plays an important role in the regulation of hormone secretion.

UI	MeSH Term	Description	Entries
D006965	Hyperplasia	An increase in the number of cells in a tissue or organ without tumor formation. It differs from HYPERTROPHY, which is an increase in bulk without an increase in the number of cells.	Hyperplasias
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D010280	Parathyroid Glands	Two pairs of small oval-shaped glands located in the front and the base of the NECK and adjacent to the two lobes of THYROID GLAND. They secrete PARATHYROID HORMONE that regulates the balance of CALCIUM; PHOSPHORUS; and MAGNESIUM in the body.	Gland, Parathyroid,Glands, Parathyroid,Parathyroid Gland
D010281	Parathyroid Hormone	A polypeptide hormone (84 amino acid residues) secreted by the PARATHYROID GLANDS which performs the essential role of maintaining intracellular CALCIUM levels in the body. Parathyroid hormone increases intracellular calcium by promoting the release of CALCIUM from BONE, increases the intestinal absorption of calcium, increases the renal tubular reabsorption of calcium, and increases the renal excretion of phosphates.	Natpara,PTH (1-84),PTH(1-34),Parathormone,Parathyrin,Parathyroid Hormone (1-34),Parathyroid Hormone (1-84),Parathyroid Hormone Peptide (1-34),Hormone, Parathyroid
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002850	Chromatography, Gel	Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.	Chromatography, Exclusion,Chromatography, Gel Permeation,Chromatography, Molecular Sieve,Gel Filtration,Gel Filtration Chromatography,Chromatography, Size Exclusion,Exclusion Chromatography,Gel Chromatography,Gel Permeation Chromatography,Molecular Sieve Chromatography,Chromatography, Gel Filtration,Exclusion Chromatography, Size,Filtration Chromatography, Gel,Filtration, Gel,Sieve Chromatography, Molecular,Size Exclusion Chromatography