A ROLE OF 1,25-DIHYDROXYVITAMIN D3 IN PHOSPHATE METABOLISM

2009 ◽  
Vol 32 (8) ◽  
pp. 247-249
PEDIATRICS ◽  
1983 ◽  
Vol 72 (2) ◽  
pp. 225-233
Author(s):  
James C. M. Chan ◽  
Reuben B. Young ◽  
Uri Alon ◽  
Peter Mamunes

Forty-two children received 1,25-dihydroxy-vitamin-D3 for treatment of disorders in calcium and phosphate metabolism secondary to chronic renal insufficiency (n = 29), sex-linked dominant hypophosphatemic rickets (n = 9), hypoparathyroidism (n = 2), and pseudohypoparathyroidism (n = 2). Serum calcium, phosphate, and creatinine concentrations were measured monthly for a mean of 26 months and a total of 1,079.5 patient-months. Patients with renal osteodystrophy manifested hypercalcemia (>11 mg/dL) once in every 13 months of treatment on the average. Of three children with hypophosphatemic rickets who experienced hypercalcemia, two proved to have tertiary hyperparathyroidism. Among children with hypoparathyroidism and pseudohypoparathyroidism, three episodes of hypercalcemia were observed during 124.5 patient-months, an incidence of one hypercalcemic episode per 39 treatment months. Renal function, as represented by reciprocals of serum creatinine determined retrospectively for a mean of 22 months before and prospectively for a mean of 26 months after initiation of 1,25-dihydroxyvitamin-D3 treatment, underwent no significant changes except in seven of 29 children with chronic renal insufficiency, six of whose rate of renal function deterioration increased on the treatment and one whose rate decreased. With one exception, hypercalcemia was associated in all cases with accelerated renal function deterioration. Before and after initiation of treatment with 1,25-dihydroxyvitamin-D3 the mean calcium x phosphate solubility products were 42.9 and 47.2, respectively. Values less than 60 are accepted as normal. Hypercalcemia is an occasional concomitant of such treatment and a more rapid deterioration of renal function may occur in some of the patients treated with 1,25-dihydroxyvitamin-D3. Thus, careful monitoring of concentrations of serum calcium, phosphate, and creatinine must accompany 1,25-dihydroxy-vitamin-D3 therapy.


1985 ◽  
Vol 11 (5-6) ◽  
pp. 331-336 ◽  
Author(s):  
Sumiko Iho ◽  
Fumiaki Kura ◽  
Hiroyuki Sugiyama ◽  
Takayuki Takahashi ◽  
Takashi Hoshino

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Laura Saldaña ◽  
Gema Vallés ◽  
Fátima Bensiamar ◽  
Francisco José Mancebo ◽  
Eduardo García-Rey ◽  
...  

Abstract Mesenchymal stem cells (MSC) modulate the macrophage-mediated inflammatory response through the secretion of soluble factors. In addition to its classical effects on calcium homeostasis, 1,25-dihydroxyvitamin D3 (1,25D3) has emerged as an important regulator of the immune system. The present study investigates whether 1,25D3 modulates the paracrine interactions between MSC and macrophages. 1,25D3 stimulated MSC to produce PGE2 and VEGF and regulated the interplay between macrophages and MSC toward reduced pro-inflammatory cytokine production. Conditioned media (CM) from co-cultures of macrophages and MSC impaired MSC osteogenesis. However, MSC cultured in CM from 1,25D3-treated co-cultures showed increased matrix maturation and mineralization. Co-culturing MSC with macrophages prevented the 1,25D3-induced increase in RANKL levels, which correlated with up-regulation of OPG secretion. MSC seeding in three-dimensional (3D) substrates potentiated their immunomodulatory effects on macrophages. Exposure of 3D co-cultures to 1,25D3 further reduced the levels of soluble factors related to inflammation and chemotaxis. As a consequence of 1,25D3 treatment, the recruitment of monocytes toward CM of 3D co-cultures decreased, while the osteogenic maturation of MSC increased. These data add new insights into the pleiotropic effects of 1,25D3 on the crosstalk between MSC and macrophages and highlight the role of the hormone in bone regeneration.


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