scholarly journals Defective binding and function of 1,25-dihydroxyvitamin D3 receptors in peripheral mononuclear cells of patients with end-organ resistance to 1,25-dihydroxyvitamin D.

1985 ◽  
Vol 76 (5) ◽  
pp. 2012-2015 ◽  
Author(s):  
R Koren ◽  
A Ravid ◽  
U A Liberman ◽  
Z Hochberg ◽  
Y Weisman ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Dihydroxyvitamin D3 ◽  
Dihydroxyvitamin D ◽  
D3 Receptors ◽  
1,25 Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D3 ◽  
Peripheral Mononuclear Cells ◽  
And Function

scholarly journals 1,25-Dihydroxyvitamin D3 and Development of Tuberculosis in Cattle

2003 ◽  
Vol 10 (6) ◽  
pp. 1129-1135 ◽  
Author(s):  
S. G. Rhodes ◽  
L. A. Terry ◽  
J. Hope ◽  
R. G. Hewinson ◽  
H. M. Vordermeier
Keyword(s):  
Vitamin D ◽  
T Cell ◽  
Mononuclear Cells ◽  
T Cell Proliferation ◽  
Accessory Cell ◽  
Dihydroxyvitamin D3 ◽  
Dihydroxyvitamin D ◽  
Cell Responses ◽  
1,25 Dihydroxyvitamin D ◽  
Accessory Cells

ABSTRACT This report describes the presence and activity of 1,25-dihydroxyvitamin D3 (1,25-D3) in experimental bovine tuberculosis. Animals that went on to develop tuberculous lesions exhibited a rapid transient increase in serum 1,25-D3 within the first 2 weeks following infection with Mycobacterium bovis. 1,25-D3-positive mononuclear cells were later identified in all tuberculous granulomas by immunohistochemical staining of postmortem lymph node tissue. These results suggest a role for 1,25-D3 both at the onset of infection and in the development of the granuloma in these infected animals. Using a monoclonal antibody to the vitamin D receptor (VDR) as a VDR agonist, we confirmed that activation of the vitamin D pathway profoundly depresses antigen-specific, but not mitogenic, bovine peripheral blood T-cell responses (proliferation and gamma interferon production). Investigation of the mechanism of this suppression showed that the VDR antibody modified the expression of CD80 by accessory cells, such that a significant positive correlation between T-cell proliferation and accessory cell CD80 emerged.

Effects of 1,25-dihydroxyvitamin D3 and cortisol on bovine and human parathyroid cells

1989 ◽  
Vol 123 (1) ◽  
pp. 137-142 ◽  
Author(s):  
R. Karmali ◽  
S. Farrow ◽  
M. Hewison ◽  
S. Barker ◽  
J. L. H. O'Riordan
Keyword(s):  
Parathyroid Hormone ◽  
Receptor Protein ◽  
Mrna Levels ◽  
Dihydroxyvitamin D3 ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D3 ◽  
Cytosolic Protein

ABSTRACT Incubation of bovine parathyroid cells with 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) decreased both preproparathyroid mRNA levels and parathyroid hormone (PTH) secretion. There was a fall to 56·6 ± 13·7% (mean ± s.e.m.) and 65·1 ± 9·3% in mRNA levels and PTH secretion respectively at 1 nmol 1,25-(OH)2D3/l, and 41·1 ± 13·6% and 42·0 ± 12·1% at 10 nmol 1,25-(OH)2D3/l after 24 h. After 48 h in 0·1 nmol 1,25-(OH)2D3/l, mRNA levels had fallen to 35·3 ± 12·6% and PTH secretion to 32·1 ± 5·0%. In human adenomatous cells, however, incubation with 1,25-(OH)2D3 (10 nmol/l) had no effect on either mRNA levels or PTH secretion even after 48 h. This lack of sensitivity of adenomatous cells to 1,25-(OH)2D3 was not due to an absence of receptors (3847 ± 39 receptors/ng cytosolic protein in adenomatous cells compared with 4068 ± 371 in bovine cells) or receptors being of low affinity. Cortisol (1 μmol/l) caused a reduction in the number of receptors for 1,25-(OH)2D3 in bovine parathyroid cells of approximately 20% within 24 h of incubation, but no change in affinity. This decrease was accompanied by abolition of the response to 1,25-(OH)2D3 and was reversible, in that withdrawal of cortisol for the final 24 h of incubation was sufficient for the response to return, the number of receptors having returned to control values. These results suggest that only a small percentage of receptors for 1,25-(OH)2D3 in bovine parathyroid cells may be functional at any one time. Furthermore, the insensitivity of human adenomatous cells to 1,25-(OH)2D3 does not seem to be due to a lack of receptors but may be due to a defect in the interaction between the receptor protein and the PTH gene. Journal of Endocrinology (1989) 123, 137–142

Effect of 1,25-dihydroxyvitamin D deficiency on the metabolic clearance rate of 1,25-dihydroxyvitamin D3: studies using pigs with vitamin D-dependent rickets type 1

1985 ◽  
Vol 69 (5) ◽  
pp. 549-552
Author(s):  
John Fox ◽  
Anthony D. Care
Keyword(s):  
Vitamin D ◽  
Clearance Rate ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Dihydroxyvitamin D3 ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D3 ◽  
Steady State Levels

1. We have used pigs with inherited vitamin D-dependent rickets type 1 to study the effect of 1,25-dihydroxyvitamin D deficiency on the metabolic clearance rate of 3H-1,25-dihydroxyvitamin D3 infused to steady-state levels in plasma. 2. Plasma levels of 1,25-dihydroxyvitamin D were 24 ± 1 (sem) pmol/l in the hypocalcaemic, homozygous piglets and 196 ± 27 pmol/l in their normocalcaemic, heterozygous siblings. 3. The metabolic clearance rate of 1,25-dihydroxyvitamin D3 was the same in both normal heterozygous (0.90 ± 0.02) and hypocalcaemic, homozygous piglets (0.90±0.01 ml−1 min−1 kg−1 metabolic bodysize). 4. We conclude that a deficiency of circulating 1,25-dihydroxyvitamin D does not influence the clearance of 1,25-dihydroxyvitamin D3 from the circulation of pigs.

scholarly journals 167 MEASUREMENT OF 1,25 DIHYDROXYVITAMIN D. RECEPTORS (VDR) IN TERM BABIES CORD PERIPHERAL MONONUCLEAR CELLS (PMN)

1994 ◽  
Vol 36 (1) ◽  
pp. 30A-30A
Author(s):  
M Moya ◽  
I Ballester ◽  
M J Campello ◽  
J De Dios ◽  
F Galán ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Peripheral Mononuclear Cells
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