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 00:00:00 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), Vol. 109:1
• Country of Publication: United States
• Language: English

Related Subjects

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