Biomaterial Database

[Activation of vitamin D 3 and the mode of action of 1,25-hydroxycholecalciferol and 24,25-hydroxycholecalciferol]. 1976

E Kolb

A survey is given on the present state of the animal-biochemical research concerning the effectivity of the D-vitamins. The vitamin D3 is transferred in 25-hydroxycholecalciferol in the microsome fraction of the liver. Then in the kidneys a transformation into the physiologically active forms - the 1,25- and the 24,25-hydroxycholecalciferol - takes place. The kind of transformation depends on the Ca- and P-supply as well as on the level of the parathormone secretion. In the mucous membrane of the small intestine the 1,25- and the 24,25-hydroxycholecalciferol stimulate the formation of the Ca-transport protein. The 1,25-hydroxycholecalciferol is above all formed in hypocalcaemia or hypophosphataemia and furthers the mobilisation of Ca- and phosphate-ions from the bones. In a liver damage disturbances of the formation of 25-hydroxycholecalciferol and in renal damage disturbances of the formation of 1,25- and 24,25-hydroxycholecalciferol may appear. A reduction of the formation of the active forms of the D-vitamins leads to a decrease of the Ca-utilisation as well as of the growth of bones.

UI	MeSH Term	Description	Entries
D007676	Kidney Failure, Chronic	The end-stage of CHRONIC RENAL INSUFFICIENCY. It is characterized by the severe irreversible kidney damage (as measured by the level of PROTEINURIA) and the reduction in GLOMERULAR FILTRATION RATE to less than 15 ml per min (Kidney Foundation: Kidney Disease Outcome Quality Initiative, 2002). These patients generally require HEMODIALYSIS or KIDNEY TRANSPLANTATION.	ESRD,End-Stage Renal Disease,Renal Disease, End-Stage,Renal Failure, Chronic,Renal Failure, End-Stage,Chronic Kidney Failure,End-Stage Kidney Disease,Chronic Renal Failure,Disease, End-Stage Kidney,Disease, End-Stage Renal,End Stage Kidney Disease,End Stage Renal Disease,End-Stage Renal Failure,Kidney Disease, End-Stage,Renal Disease, End Stage,Renal Failure, End Stage
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D001842	Bone and Bones	A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principal cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.	Bone Tissue,Bone and Bone,Bone,Bones,Bones and Bone,Bones and Bone Tissue,Bony Apophyses,Bony Apophysis,Condyle,Apophyses, Bony,Apophysis, Bony,Bone Tissues,Condyles,Tissue, Bone,Tissues, Bone
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
D002762	Cholecalciferol	Derivative of 7-dehydroxycholesterol formed by ULTRAVIOLET RAYS breaking of the C9-C10 bond. It differs from ERGOCALCIFEROL in having a single bond between C22 and C23 and lacking a methyl group at C24.	Vitamin D 3,(3 beta,5Z,7E)-9,10-Secocholesta-5,7,10(19)-trien-3-ol,Calciol,Cholecalciferols,Vitamin D3
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006887	Hydroxycholecalciferols	Hydroxy analogs of vitamin D 3; (CHOLECALCIFEROL); including CALCIFEDIOL; CALCITRIOL; and 24,25-DIHYDROXYVITAMIN D 3.	Hydroxyvitamins D,Hydroxycholecalciferol
D006900	Hydroxylation	Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)	Hydroxylations
D001682	Biological Availability	The extent to which the active ingredient of a drug dosage form becomes available at the site of drug action or in a biological medium believed to reflect accessibility to a site of action.	Availability Equivalency,Bioavailability,Physiologic Availability,Availability, Biologic,Availability, Biological,Availability, Physiologic,Biologic Availability,Availabilities, Biologic,Availabilities, Biological,Availabilities, Physiologic,Availability Equivalencies,Bioavailabilities,Biologic Availabilities,Biological Availabilities,Equivalencies, Availability,Equivalency, Availability,Physiologic Availabilities
D012279	Rickets	Disorders caused by interruption of BONE MINERALIZATION manifesting as OSTEOMALACIA in adults and characteristic deformities in infancy and childhood due to disturbances in normal BONE FORMATION. The mineralization process may be interrupted by disruption of VITAMIN D; PHOSPHORUS; or CALCIUM homeostasis, resulting from dietary deficiencies, or acquired, or inherited metabolic, or hormonal disturbances.	Rachitis,Rachitides