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The influence of short-(7 days) and long-term (28 days) hypokinesia on 25-hydroxyvitamin D3 metabolism was investigated in rats fed on a normal calcium (0.6%), normal phosphorus (0.6%), vitamin D-supplemented diet. The animals were given a single intraperitoneal dose of tritiated [26,27-3H]25(OH)D3 (200 pmol) eighteen hours before sacrifice. [3H]Labelled vitamin D3 metabolites were separated by high performance liquid chromatographic procedure, and their radioactivity levels in serum, kidney, intestinal mucosa and femoral bone were measured. Long-term hypokinesia resulted in decreased levels of [3H]1.25(OH)2D3 and increased levels of [3H]24.25(OH)2D3 in serum and kidney (3.15 +/- 0.62 vs. 4.33 +/- 0.41% and 5.34 +/- 0.69 vs. 3.76 +/- 0.29% for [3H]1.25(OH)2D3 and [3H]24.25(OH)2D3 in serum; 7.52 +/- 0.69 vs. 11.6 +/- 0.79% and 9.33 +/- 0.55 vs. 5.94 +/- 0.24% for those in kidney). The levels of [3H]1.25(OH)2D3 as well as of [3H] 24.25(OH)2D3 were decreased in intestinal mucosa and bone (21.5 +/- 1.46 vs. 30.1 +/- 3.04% and 7.30 +/- 0.58 vs. 9.18 +/- 0.78% for [3H]1.25(OH)2D3 and [3H]24.25(OH)2D3 in intestinal mucosa; 6.39 +/- 06.5 vs. 11.5 +/- 1.64% and 7.78 +/- 0.71 vs. 13.9 +/- 1.28% for those in bone). The data obtained suggest a suppressed synthesis of 1.25(OH)2D3 and enhanced production of 24.25(OH)2D3 in kidney as well as a diminished binding of 24.25(OH)2D3 in intestinal mucosa and bone in hypothetic rats. Possible causes of variations in biosynthesis of vitamin D3 active metabolites, and role of these variations in the disorders of calcium metabolism and bone state during hypokinesia are discussed.
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
January 1981,
Journal of nutritional science and vitaminology,
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
January 1987,
The American journal of physiology,
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
May 1977,
Calcified tissue research,
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
December 1976,
Life sciences,
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
August 1990,
Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research,
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
April 1977,
Biochemical and biophysical research communications,
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
July 1983,
Calcified tissue international,
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
February 1974,
Proceedings of the National Academy of Sciences of the United States of America,
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
July 1998,
Archives of biochemistry and biophysics,
I N Sergeev, and
Iu P Arkhapchev, and
L F Linberg, and
N V Blazheevich, and
A S Ushakov
May 1989,
Endocrinology,
