Effects of 1α-hydroxyvitamin D3 and 24R,25-dihydroxyvitamin D3 on bone remodeling

Galus, K; Szymendera, J; Zaleski, Amanda L.; Schreyer, Kraftin E.

doi:10.1007/bf02407183

Cited by 29 publications

(15 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, 24,25(OH)2D3 enhanced the mineralization of previously formed osteoid in the absence of any quantitative effect on the rates of either bone or matrix formation. These findings agree with those of Galus et al [17] who found a reduction in the width of osteoid seams in osteomalacic dogs given 24,25(OH)zD 3. The present results differ, however, in that increments in the rate of bone apposition, as reported by these investigators, were not observed.…”

Section: 25(oh)2d 3 Is the Most Active Metabolite Of Vitamin D On Asupporting

confidence: 94%

24,25(OH)2D3, bone formation, and bone resorption in vitamin D-deficient, azotemic rats

1984

View full text Add to dashboard Cite

Bone formation, mineralization, and resorption were measured in vitamin D-deficient, azotemic rats given two different dosages of 24,25(OH)2D3 daily and in vehicle-treated controls (C). The intraperitoneal administration of 65 pmol over a 10 day period corrected the hypocalcemia observed in C, whereas 130 pmol produced mild hypercalcemia. Both dosages reduced osteoid width, osteoid area, and mineralization front width from control values. The rates of bone and matrix formation were unaffected by treatment. In C, matrix formation exceeded bone formation and resulted in osteoid accumulation; both dosages of 24,25(OH)2D3 reversed this relationship such that bone formation exceeded matrix formation in each treatment group. The rates of osteoid maturation and initial mineralization increased during repletion with 24,25(OH)2D3 at both dosage levels. However, the serum calcium concentration was correlated with both osteoid maturation rate (r = 0.68, P less than 0.01) and initial mineralization rate (r = 0.63, P less than 0.01) when all three experimental groups were considered. Bone resorption was unchanged from control values during treatment with 24,25(OH)2D3. The results suggest that 24,25(OH)2D3 promotes the maturation and mineralization of osteoid, and that this metabolite differs in its effects on bone formation and resorption. It is not clear, however, that the changes in bone dynamics observed are independent of the calcemic response induced by metabolite repletion under the conditions of this experiment.

show abstract

Section: 25(oh)2d 3 Is the Most Active Metabolite Of Vitamin D On Asupporting

confidence: 94%

24,25(OH)2D3, bone formation, and bone resorption in vitamin D-deficient, azotemic rats

1984

View full text Add to dashboard Cite

show abstract

“…In this context it should be mentioned that when 24,25(OH)2D3 was administered to rachitic dogs the number of resorption cavities and the length of resorption sites was reduced to normal concomitantly with an increase in the rate of oppositional growth of bone [Ornoy et al, 1978;Gallus et al, 1980]. Our results further corroborate different previous studies [Dekel et al, 1979;Edelstein and Ornoy, 1979], pointing towards a major role of 24,25(OH)2D3 in bone metabolism.…”

Section: Discussionsupporting

confidence: 82%

Transplacental Effects of 1,25-Dihydroxycholecaiciferol and of 24,25-Dihydroxycholecalciferol on the Limb Skeleton of Fetuses and Offspring of Rats

Zusman

Hirsh

Edelstein

et al. 1981

Cells Tissues Organs

View full text Add to dashboard Cite

The transplacental effects of 1,25(OH)₂D₃ and of 24,25(OH)₂D₃ on bone formation in rat fetuses and pups have been investigated. Pregnant rats treated with 1,25(OH)₂D₃ or with 1,25(OH₂D₃ and 24,25(OH)₂D₃ showed hypercalcemia, while those treated with 24,25(OH)₂D₃ did not. Fetal weight was markedly reduced by treatment with 1,25(OH)₂D₃ and not with 24,25(OH)₂D₃ or with a combination of both metabolites. Microscopical examination of fetal long bones showed after treatment with 1,25(OH)₂D₃ a marked reduction in diaphysial length. Diaphyseal trabeculae were thin and disorganized. The epiphysis had a thinner layer of hypertrophic and calcified cartilage. The numbers of osteoclasts in the diaphysis and metaphysis were the same as in controls. Treatment with 24,25(OH)₂D₃ did not affect fetal bone length; many bone trabeculae were found in the diaphyseal cavity leaving small bone marrow spaces; the number of osteoclasts in the metaphysis and in the diaphysis was increased. All changes in the skeleton disappeared during the first week after birth. It can be suggested that high doses of 1,25(OH)₂D₃ inhibit bone formation and maturation of cartilage. The addition of 24,25(OH)₂D₃ to 1,25(OH)₂D₃ seemed to reduce the toxic effects of the latter on the fetal skeleton. These results point to a definite difference between the action of high doses of 1,25(OH)₂D₃ and 24,25(OH)₂D₃ on fetal bone.

show abstract

“…There is a growing body of evidence that both 1,25-(OH) 2 D and 24,25-(0H) 2 D are required for optimal vitamin D action on bone formation, mineralization, and remodelling (3,5,(52)(53)(54). In vitamin D-depleted dogs with osteomalacia, the administration of either metabolite increased the rate of appositional bone growth.…”

Section: Discussionmentioning

confidence: 97%

Plasma Concentrations of Vitamin D Metabolites in Puberty: Effect of Sexual Maturation and Implications for Growth*

Aksnes

Aarskog

1982

The Journal of Clinical Endocrinology & Metabolism

130

View full text Add to dashboard Cite

To relate the vitamin D metabolism in puberty to sex, sexual maturation, and, indirectly, to growth velocity and cessation of growth, the plasma level of 25-hydroxy vitamin D, 1,25-dihydroxyvitamin D [1,25-(OH)2D], 24,25-dihydroxyvitamin D [24,25-(OH)2D], and 25,26-(OH)2D were measured in 191 adolescents representing all stages of puberty. In girls, 1,25-(OH)2D3 increased from age 11 yr to a peak at 12 yr of age (P less than 0.0005) and then decreased. In boys, the increase occurred between 13--14 yr of age (P less than 0.005), with a subsequent decline. When the 1,25-(OH)2D concentrations were related to the stage of puberty, the girls showed a maximal increase between stages 1 and 2 (P less than 0.0005), with a peak at stage 3, whereas the boys had a significant increase from stage 2 to a peak at stage 3 (P less than 0.01). In both sexes, there were subsequent significantly decreasing values to stage 4 through stage 5. The ratio of 24,25-(OH)2D to 25-hydroxyvitamin D varied inversely with the 1,25-(OH)2D concentration, with the lowest value at age 12 yr in both sexes, followed by a gradual increase to a plateau at age 15 yr in girls and 17 yr in boys. It appears that the hormones of the vitamin D system add another dimension to the endocrinology of growth and puberty.

show abstract

Effects of 1α-hydroxyvitamin D3 and 24R,25-dihydroxyvitamin D3 on bone remodeling

Cited by 29 publications

References 20 publications

24,25(OH)2D3, bone formation, and bone resorption in vitamin D-deficient, azotemic rats

24,25(OH)2D3, bone formation, and bone resorption in vitamin D-deficient, azotemic rats

Transplacental Effects of 1,25-Dihydroxycholecaiciferol and of 24,25-Dihydroxycholecalciferol on the Limb Skeleton of Fetuses and Offspring of Rats

Plasma Concentrations of Vitamin D Metabolites in Puberty: Effect of Sexual Maturation and Implications for Growth*

Contact Info

Product

Resources

About