Biomaterial Database

Renal regulation of avian calcium and phosphorus metabolism. 1987

R F Wideman

Avian plasma calcium (Ca) and inorganic phosphate (Pi) concentrations are coregulated by parathyroid hormone (PTH) and vitamin D acting directly or indirectly on the intestine, bone and kidneys. Within the overall scheme of chemical, hormonal and target tissue interactions, the kidneys serve as a safety valve, operating on a minute-to-minute basis to excrete Ca and Pi when these minerals are present in excess or to conserve Ca and Pi when they are needed for eggshell formation or bone mineral replenishment. This key role of the kidneys is directly mediated by PTH, acting to stimulate Ca reabsorption and increase Pi excretion at the tubular level. By dissociating Ca from Pi transport, the kidneys serve to maintain appropriate blood Ca:Pi concentration ratios during extremes of dietary challenge or bone mineral mobilization. Direct regulatory roles for vitamin D metabolites and calcitonin on avian urinary Ca and Pi excretion have yet to be firmly established.

UI	MeSH Term	Description	Entries
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
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
D010758	Phosphorus	A non-metal element that has the atomic symbol P, atomic number 15, and atomic weight 31. It is an essential element that takes part in a broad variety of biochemical reactions.	Black Phosphorus,Phosphorus-31,Red Phosphorus,White Phosphorus,Yellow Phosphorus,Phosphorus 31,Phosphorus, Black,Phosphorus, Red,Phosphorus, White,Phosphorus, Yellow
D011200	Poultry	Domesticated birds raised for food. It typically includes CHICKENS; TURKEYS, DUCKS; GEESE; and others.	Fowls, Domestic,Domestic Fowl,Domestic Fowls,Fowl, Domestic,Poultries
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
D004032	Diet	Regular course of eating and drinking adopted by a person or animal.	Diets
D004531	Eggs	Animal reproductive bodies, or the contents thereof, used as food. The concept is differentiated from OVUM, the anatomic or physiologic entity.
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014807	Vitamin D	A vitamin that includes both CHOLECALCIFEROLS and ERGOCALCIFEROLS, which have the common effect of preventing or curing RICKETS in animals. It can also be viewed as a hormone since it can be formed in SKIN by action of ULTRAVIOLET RAYS upon the precursors, 7-dehydrocholesterol and ERGOSTEROL, and acts on VITAMIN D RECEPTORS to regulate CALCIUM in opposition to PARATHYROID HORMONE.