Biomaterial Database

Biological activity of 1,25-dihydroxyvitamin D2 and 24-epi-1,25-dihydroxyvitamin D2. 1988

H F DeLuca, and R R Sicinski, and Y Tanaka, and P H Stern, and C M Smith

Department of Biochemistry, University of Wisconsin-Madison 53706.

The biological activity of 1,25-dihydroxyvitamin D2 [1,25(OH)2D2] and 24-epi-1,25-dihydroxyvitamin D2 [24-epi-1,25(OH)2D2] has been determined in vitamin D-deficient rats. The biological effectiveness of 1,25(OH)2D2 is equal to that reported previously for 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] (15) in intestinal calcium transport, mineralization of bone, mobilization of bone calcium, and elevation of plasma inorganic phosphorus of rachitic rats. However, 24-epi-1,25(OH)2D2 is at best one-half as active as 1,25(OH)2D2 in stimulating intestinal calcium transport and in the mineralization of rachitic bone. The 24-epi-1,25(OH)2D2 is one-third as active as 1,25(OH)2D3 in binding to the chick intestinal receptor for 1,25(OH)2D3. Thus receptor discrimination may account for the twofold difference in intestinal calcium transport activity. 24-Epi-1,25(OH)2D2 appeared inactive in in vivo mobilization of bone calcium or bone phosphorus. On the other hand, in fetal rat bone in culture, the epi compound was only five times less active than 1,25(OH)2D2 in inducing resorption. Short-term experiments on bone mineral mobilization in vivo show that the 24-epi-1,25(OH)2D2 does induce bone calcium mobilization but that its activity in this respect is short lived. It is suggested that 24-epi-1,25(OH)2D2 and, as a result, it shows preferential activity on intestine whose response to a single dose of 1,25(OH)2D2 remains for several days, whereas the short-lived bone system does not remain stimulated during the 24-h period between doses.

UI	MeSH Term	Description	Entries
D007408	Intestinal Absorption	Uptake of substances through the lining of the INTESTINES.	Absorption, Intestinal
D007413	Intestinal Mucosa	Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.	Intestinal Epithelium,Intestinal Glands,Epithelium, Intestinal,Gland, Intestinal,Glands, Intestinal,Intestinal Gland,Mucosa, Intestinal
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D011987	Receptors, Steroid	Proteins found usually in the cytoplasm or nucleus that specifically bind steroid hormones and trigger changes influencing the behavior of cells. The steroid receptor-steroid hormone complex regulates the transcription of specific genes.	Corticosteroid Receptors,Receptors, Corticosteroid,Steroid Receptors,Corticosteroid Receptor,Receptors, Steroids,Steroid Receptor,Receptor, Corticosteroid,Receptor, Steroid,Steroids Receptors
D012016	Reference Values	The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.	Normal Range,Normal Values,Reference Ranges,Normal Ranges,Normal Value,Range, Normal,Range, Reference,Ranges, Normal,Ranges, Reference,Reference Range,Reference Value,Value, Normal,Value, Reference,Values, Normal,Values, Reference
D001862	Bone Resorption	Bone loss due to osteoclastic activity.	Bone Loss, Osteoclastic,Osteoclastic Bone Loss,Bone Losses, Osteoclastic,Bone Resorptions,Loss, Osteoclastic Bone,Losses, Osteoclastic Bone,Osteoclastic Bone Losses,Resorption, Bone,Resorptions, Bone
D002117	Calcitriol	The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption.	1 alpha,25-Dihydroxycholecalciferol,1 alpha,25-Dihydroxyvitamin D3,1, 25-(OH)2D3,1,25(OH)2D3,1,25-Dihydroxycholecalciferol,1,25-Dihydroxyvitamin D3,1 alpha, 25-dihydroxy-20-epi-Vitamin D3,1,25(OH)2-20epi-D3,1,25-dihydroxy-20-epi-Vitamin D3,20-epi-1alpha,25-dihydroxycholecaliferol,Bocatriol,Calcijex,Calcitriol KyraMed,Calcitriol-Nefro,Decostriol,MC-1288,MC1288,Osteotriol,Renatriol,Rocaltrol,Silkis,Sitriol,Soltriol,Tirocal,1 alpha,25 Dihydroxyvitamin D3,1,25 Dihydroxycholecalciferol,1,25 Dihydroxyvitamin D3,1,25 dihydroxy 20 epi Vitamin D3,Calcitriol Nefro,D3, 1 alpha,25-Dihydroxyvitamin,D3, 1,25-Dihydroxyvitamin,D3, 1,25-dihydroxy-20-epi-Vitamin,KyraMed, Calcitriol,MC 1288
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
D002645	Chickens	Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.	Gallus gallus,Gallus domesticus,Gallus gallus domesticus,Chicken