Hypercalciuric Hypophosphatemic Rickets, Mineral Balance, Bone Histomorphometry, and Therapeutic Implications of Hypercalciuria

PEDIATRICS ◽  
1989 ◽  
Vol 84 (2) ◽  
pp. 276-280
Author(s):  
C. Chen ◽  
T. Carpenter ◽  
N. Steg ◽  
R. Baron ◽  
C. Anast
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Hypophosphatemic Rickets ◽  
Balance Study ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Study Results ◽  
Calcium And Phosphorus

A 14-year-old Turkish boy had severe rickets that had been clinically evident since he was 2 years of age. When he was 5 years of age, he had normal serum calcium and phosphorus levels and increased alkaline phosphatase activity. Treatment with modest dosages of vitamin D (5000 U/d for 3 weeks) resulted in hypercalcemia. At 10 years of age, high-dose vitamin D (40 000 U/d) plus phosphorus (1.1 g/d) therapy for 20 days resulted in symptomatic nephrolithiasis. When, 14 years of age, he had normocalcemia, hypophosphatemia, increased alkaline phosphatase activity, and normal circulating parathyroid hormone concentration. Levels of 25-hydroxyvitamin D were normal but those of 1,25-dihydroxyvitamin D were markedly increased. Rickets and osteopenia were evident on radiographs, and osteomalacia was present on trabecular bone obtained at biopsy. Balance study results showed increased intestinal absorption of calcium and phosphorus, hypercalciuria, and increased urinary phosphorus excretion. This patient manifests an unusual form of hypophosphatemic rickets in which hypercalciuria is a cardinal feature. In contrast with most varieties of hypophosphatemia, this disorder is characterized by appropriately increased production of 1,25-dihydroxyvitamin D in response to hypophosphatemia. It is recommended that urinary calcium excretion be assessed in all patients with hypophosphatemic rickets so that appropriate therapy will be instituted.

scholarly journals Identification of intestinal cells responsive to calcitriol (1,25-dihydroxycholecalciferol)

1985 ◽  
Vol 225 (1) ◽  
pp. 127-133 ◽  
Author(s):  
M W Smith ◽  
M E Bruns ◽  
E D M Lawson
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Quantitative Description ◽  
Intestinal Cells ◽  
Protein Levels ◽  
High Affinity ◽  
Hormone Injection ◽  
Crypt Cells

The location of intestinal cells taken from the base of the crypt to the tip of the villus responsive to calcitriol (1,25-dihydroxycholecalciferol) and the distribution of [3H]calcitriol within the intestinal epithelium has been determined in vitamin D-deficient rats. The calcitriol responses examined were CaBP (Ca2+-binding protein) levels as measured by immunodiffusion and alkaline phosphatase levels as determined cytochemically. Calcitriol had no effect on villus structure or on enterocyte kinetics. This made it possible to compare levels of CaBP and alkaline phosphatase activity in enterocytes at different ages in rats at known times after hormone injection. Cells from both the crypt and villus synthesized CaBP in response to calcitriol. Alkaline phosphatase activity was not detectable in crypt cells, although a pool of precursor was produced in these cells in response to calcitriol. Enzyme activity was increased in all villus cells in response to calcitriol, but the quantitative description of this effect was very different from that found for calcitriol effects on CaBP synthesis. Calcitriol injected into vitamin D-deficient rats was detected, within 2h, in all cells of the crypt and villus. Most of the binding was to sites having a high affinity for the injected hormone.

Circulating levels of 1,25 dihydroxyvitamin D, alkaline phosphatase, hydroxyproline, and osteocalcin associated with antler growth in white-tailed deer

1988 ◽  
Vol 118 (3) ◽  
pp. 407-414 ◽  
Author(s):  
Karen L. Van Der Eems ◽  
Robert D. Brown ◽  
Caren M. Gundberg
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Serum Alkaline Phosphatase ◽  
Serum Samples ◽  
Serum Alkaline Phosphatase Activity ◽  
Dihydroxyvitamin D ◽  
Antler Growth ◽  
Antler Cycle

Abstract. Alkaline phosphatase, hydroxyproline, osteocalcin, and 1,25(OH)2D were measured in biweekly serum samples obtained from 6 adult (> 4 years), 4 juvenile (1–4 years) and 4 fawn (< 1 year) male white-tailed deer from Oct. 1983 to Oct. 1984. Antler length, from the pedicle to the tip, was measured at the time of serum sampling. Serum alkaline phosphatase activity and levels of hydroxyproline and osteocalcin were higher (P < 0.05) in fawns compared with juveniles and adults reflecting increased bone metabolism in the younger deer. In adult deer serum alkaline phosphatase activity and hydroxyproline levels were elevated (P < 0.05) during the period of antler growth, whereas serum osteocalcin and 1,25(OH)2D increased (P < 0.05) during antler mineralization. Similar but less pronounced trends occurred in juvenile deer, possibly a reflection of skeletal growth in the younger animals. The data lend support for utilization of the deer antler cycle as a model for studies of bone disorders. Further work is needed to help clarify the role of hydroxyproline, osteocalcin, and 1,25(OH)2D in the antler cycle.

Responses of serum calcium and phosphorus in the frog Rana tigrina to injection of various vitamin D analogs

1987 ◽  
Vol 65 (8) ◽  
pp. 2111-2112 ◽  
Author(s):  
Ajai K. Srivastav ◽  
L. Rani ◽  
K. Swarup
Keyword(s):  
Vitamin D ◽  
Serum Calcium ◽  
Vitamin D Analogs ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Rana Tigrina ◽  
Calcium Deposits ◽  
25 Hydroxyvitamin D ◽  
Calcium And Phosphorus

Intraperitoneal injections of either vitamin D3 (4 IU/100 g body wt.), 25 hydroxyvitamin D3 (100 ng/100 g body wt.), or 1,25 dihydroxyvitamin D3 (100 ng/100 g body wt.) for 15 days induced hypercalcemia, hyperphosphatemia, and depletion of calcium deposits in the paravertebral lime sacs in an anuran, Rana tigrina.

Enhancement of vitamin D3 effect on bone metabolism in weanling rats orally administered zinc sulphate

1986 ◽  
Vol 111 (2) ◽  
pp. 285-288 ◽  
Author(s):  
Masayoshi Yamaguchi ◽  
Teruyuki Sakashita
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Bone Metabolism ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Dna Content ◽  
Zinc Sulphate ◽  
Simultaneous Administration ◽  
Weanling Rats ◽  
Stimulation Of

Abstract. The interaction of vitamin D3 and zinc on bone metabolism was investigated in the femur of weanling rats. Oral administration of vitamin D3 (1.0 μg/100 g body weight) did not cause any increase in the zinc accumulation in the femoral tissue following treatment with zinc sulphate (1.0 mg Zn/100 g). Administration of vitamin D3 or zinc produced significant increases the alkaline phosphatase activity and DNA content of the femoral diaphvsis but not of the epiphysis. The increase in alkaline phosphatase activity was enhanced additionally by simultaneous administration of vitamin D3 and zinc. Moreover, the increase in DNA content was enhanced markedly (about 4 times) by these treatments. At a dose of 0.5 μg of vitamin D3 per 100 g, DNA content was at the control level. This level was increased about 2 times by simultaneous administration of zinc (1.0 mg/100 g). The increase in alkaline phosphatase activity following simultaneous administration of vitamin D3 and zinc was significantly inhibited by treatment with cycloheximide, actinomycin D, or mitomycin C. Also, the increase in DNA content was completely inhibited by mitomycin C treatment. The present data suggest that the combination of vitamin D3 and zinc has a multiple effect on the stimulation of bone growth and mineralization in weanling rats, and that this effect is based on a stimulation of the DNA synthesis in bone cells.

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