Wronski T J, Halloran B P, Bikle D D, Globus R K, Morey-Holton E R
Endocrinology. 1986 Dec;119(6):2580-5. doi: 10.1210/endo-119-6-2580.
Male Sprague-Dawley rats were infused continuously for 13 days with vehicle or 75 pmol (31.2 ng)/day 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] by means of Alzet osmotic minipumps implanted s.c. Animals infused with 1,25-(OH)2D3 exhibited mild hypercalcemia (11.2 vs. 10.2 mg/dl in controls), a 136% increase in the serum concentration of 1,25-(OH)2D3 (187 vs. 79 pg/ml), and a 59% decrease in serum 25-hydroxyvitamin D (12 vs. 29 ng/ml). The proximal tibial metaphysis of these animals was characterized by increased trabecular bone volume (15% vs. 6.5%), osteoid accumulation (4.2% vs. 0.1%), increased osteoblast surface and number (31% and 19/mm vs. 21% and 14/mm, respectively), and decreased osteoclast surface and number (11% and 2/mm vs. 36% and 6/mm, respectively). Similar but less striking changes were seen in the lumbar vertebra. Increases in the fat-free weight and calcium content of the tibia and lumbar vertebra were consistent with the increase in trabecular bone volume after 1,25-(OH)2D3 infusion. However, tetracycline labeling and the incorporation of 45Ca in these bones were reduced by 1,25-(OH)2D3 infusion. In addition, mineralization lag time was prolonged in the lumbar vertebrae of 1,25-(OH)2D3-infused rats. Our findings indicate that chronic 1,25-(OH)2D3 administration increases bone mass, but at the cost of impaired bone mineralization.
通过皮下植入Alzet渗透微型泵，给雄性Sprague-Dawley大鼠连续13天输注溶媒或75皮摩尔（31.2纳克）/天的1,25-二羟基维生素D3 [1,25-(OH)2D3]。输注1,25-(OH)2D3的动物出现轻度高钙血症（11.2毫克/分升，而对照组为10.2毫克/分升），血清1,25-(OH)2D3浓度增加136%（187皮克/毫升，而对照组为79皮克/毫升），血清25-羟基维生素D降低59%（12纳克/毫升，而对照组为29纳克/毫升）。这些动物的胫骨近端干骺端表现为小梁骨体积增加（15%对6.5%）、类骨质积聚（4.2%对0.1%）、成骨细胞表面和数量增加（分别为31%和19/毫米，而对照组分别为21%和14/毫米）以及破骨细胞表面和数量减少（分别为11%和2/毫米，而对照组分别为36%和6/毫米）。在腰椎也观察到类似但不太明显的变化。输注1,25-(OH)2D3后，胫骨和腰椎的去脂重量和钙含量增加，这与小梁骨体积增加一致。然而，输注1,25-(OH)2D3会使这些骨骼中的四环素标记和45Ca掺入减少。此外，输注1,25-(OH)2D3的大鼠腰椎矿化延迟时间延长。我们的研究结果表明，长期给予1,25-(OH)2D3可增加骨量，但代价是骨矿化受损。
