Effect of hypercalcemia-producing tumor on 1,25(OH)2D3 biosynthesis in athymic mice.
Effect of hypercalcemia-producing tumor on 1,25(OH)2D3 biosynthesis in athymic mice.
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产生高钙血症的肿瘤对无胸腺小鼠 1,25(OH)2D3 生物合成的影响。
DOI:
10.1152/ajpendo.1989.256.2.e309
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发表时间:
1989
期刊:
影响因子:
--
通讯作者:
Favus,MJ
中科院分区:
文献类型:
--
作者:
Kukreja,SC;York,PA;Nalbantian-Brandt,C;Shevrin,DH;Favus,MJ
Serum 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] levels are low in patients with malignancy-associated hypercalcemia (MAH), whereas murine models of MAH have high circulating 1,25(OH)2D3. To determine the effects of a hypercalcemia-producing tumor on circulating 1,25(OH)2D3, in vitro 25-hydroxyvitamin D1-hydroxylase (1OHase) activity was measured in kidneys from BALB/c athymic mice implanted with a hypercalcemia-producing human lung tumor. Twelve days of low-phosphorus diet (LPD) in control animals lowered serum phosphorus to levels found in tumor-bearing mice fed normal phosphorus diet (NPD; 4.1 +/- 0.3 vs. 4.4 +/- 0.7 mg/dl, P = NS) and increased 1OHase activity (1.6 +/- 0.2 vs. 3.9 +/- 0.7 pmol.mg protein-1.5 min-1, NPD vs. LPD, P less than 0.05). 1OHase activity was greater in tumor-bearing animals fed NPD compared with control animals fed LPD (8.4 +/- 0.6 vs. 3.9 +/- 0.7 pmol.mg protein-1.5 min-1, P less than 0.01). High-phosphorus intake suppressed 1OHase activity in both control and tumor-bearing animals. Seven days of parathyroid hormone infusion in control animals fed NPD raised serum calcium (9.4 +/- 0.2 vs. 13.3 +/- 1.6 mg/dl, P less than 0.05) and suppressed 1OHase activity (0.25 +/- 0.02 vs. 0.02 +/- 0.002 pmol.mg protein-1.5 min-1, P less than 0.001). The inverse relationship of serum phosphorus and 1OHase activity was much steeper in the tumor-bearing animals, with greater enzyme activity at comparable levels of serum phosphorus. The present study indicates that 1) factors produced by the tumor stimulate 1OHase activity, and 2) hypophosphatemia is required for expression of enhanced enzyme activity.
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影响因子:
158.5
作者:
STEWART A F;HORST R;BROADUS A E
通讯作者:
BROADUS A E
影响因子:
56.9
作者:
HUGHES, MR;BRUMBAUGH, PF;BAYLINK, DJ
通讯作者:
BAYLINK, DJ
DOI:
10.1210/jcem-53-4-833
发表时间:
1981
期刊:
The Journal of clinical endocrinology and metabolism
影响因子:
--
作者:
Riggs,BL;Hamstra,A;DeLuca,HF
通讯作者:
DeLuca,HF
影响因子:
4.8
作者:
K. Hove;R. Horst;E. Littledike;D. Beitz
通讯作者:
D. Beitz
DOI:
10.1172/jci111984
发表时间:
1985
期刊:
The Journal of clinical investigation
影响因子:
--
作者:
Mundy,GR;Ibbotson,KJ;D'Souza,SM
通讯作者:
D'Souza,SM