Conversion of 25-hydroxyvitamin D3 to 1,25-dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 in renal slices from the rat

Journal Article · Wed Jul 01 04:00:00 EDT 1981 · Endocrinology; (United States)

OSTI ID:5615359

Armbrecht, H J; Zenser, T V; Davis, B B

Isolated renal cortical slices were used to study the conversion of 25-hydroxyvitamin D3 to 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and 24,25-dihydroxyvitamin D3 (24,25)(OH2)D3) by the rat kidney. Production of 1,25-(OH)2D3 and 24,25-(OH)2D3 was linear with time (30-90 min) and tissue weight (40-250 mg). Production of 1,25-(OH)2D3 was greatest (134 +/- 17 pg/mg tissue.h) in animals fed a low calcium, vitamin D-deficient diet. The greatest 24,25-(OH)2D3 production (106 +/- 17 pg/mg tissue.h) was seen in animals fed a high calcium, vitamin D-replete diet, 1,25-(OH)2D3 production was reduced to 23% of maximum by the addition of 1.2% calcium or 0.8% strontium to the vitamin D-deficient, low calcium diet. Production of 1,25-(OH)2D3 and 24,25-(OH)2D3 was greatly reduced in renal cortical slices that had been heated before incubation. Slices of renal medulla produced only small amounts of 1,25-(OH)2D3 compared to slices of renal cortex. These studies provide direct evidence for the production of 1,25-(OH)2D3 and 24,25-(OH)2D3 by the mammalian renal cortex. They also demonstrate that this production may be modulated by dietary calcium, strontium, and vitamin D.

• OSTI ID: 5615359
• Journal Information: Endocrinology; (United States), Journal Name: Endocrinology; (United States) Vol. 109:1; ISSN ENDOA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
551000 -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH METALS
ANIMALS
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
BODY
CALCIUM
CHOLECALCIFEROL
DIET
ELEMENTS
KIDNEYS
KINETICS
MAMMALS
METALS
NUTRITIONAL DEFICIENCY
ORGANS
PHYSIOLOGY
RATS
REACTION KINETICS
RODENTS
STRONTIUM
SYNTHESIS
VERTEBRATES
VITAMIN D
VITAMINS