Nakatsuka K, Kosaka H, Kiichiro S, Takamoto S, Onishi T, Miki T, Nishizawa Y, Morii H
Second Department of Internal Medicine, Osaka City University Medical School.
Nihon Ronen Igakkai Zasshi. 1997 Sep;34(9):733-8. doi: 10.3143/geriatrics.34.733.
Serum bone Gla-protein (BGP) is produced by osteoblasts in a vitamin K-dependent process. It is well known that serum BGP levels increase after oral administration of active vitamin D3 in postmenopausal women and patients with chronic renal failure before dialysis. These findings indicate that active vitamin D3 increases the BGP production by osteoblasts. In the present study, a daily oral dose of 2 micrograms of 1 alpha (OH)D3 was administered to 10 elderly males (age, 75.0 +/- 10.9 years) and 8 young males (age, 29.0 +/- 3.2 years) to compare the changes in serum BGP levels between the two groups. None of the subjects had severe renal or hepatic dysfunction or abnormalities in calcium (Ca) metabolism. Serum BGP and 1,25(OH)2D levels in both groups were measured before the initial administration, at 24 h and at 1, 2 and 3 weeks after the start of administration. Serum parathyroid hormone (m-PTH), alkaline phosphatase (ALP), Ca and phosphorus levels were also measured in the elderly group. Serum BGP levels before the initial administration were 4.63 +/- 1.8 ng/ml in the elderly group and 4.33 +/- 0.92 ng/ml in the young group, with no significant difference between the two groups. In both group serum 1,25(OH)2D levels were slightly increased at 24 h after administration. In the elderly group serum BGP levels increased significantly to 11.5 +/- 3.0 ng/ml, an increase of approximately 250%, 1 week after the initial administration and the increase was maintained for up to 3 weeks after the administration commenced. However, no changes in serum BGP levels were noted in the young group. In the elderly group serum m-PTH levels were 544 +/- 257 pg/ml, almost the upper normal limit, before, and decreased slightly after, the administration of 1 alpha (OH)D3. Serum ALP levels also decreased slightly after the administration and serum Ca levels were slightly increased, however, the changes were within normal limits. We conclude that osteoblastic function is activated after short-term administration of active vitamin D3 in vitamin D deficient elderly subjects.
血清骨钙素（BGP）由成骨细胞在维生素K依赖的过程中产生。众所周知，绝经后女性和透析前慢性肾衰竭患者口服活性维生素D3后血清BGP水平会升高。这些发现表明活性维生素D3可增加成骨细胞的BGP生成。在本研究中，给10名老年男性（年龄75.0±10.9岁）和8名年轻男性（年龄29.0±3.2岁）每日口服2微克的1α（OH）D3，以比较两组血清BGP水平的变化。所有受试者均无严重肾或肝功能障碍或钙（Ca）代谢异常。在初次给药前、给药后24小时以及给药开始后1、2和3周测量两组的血清BGP和1,25（OH）2D水平。老年组还测量了血清甲状旁腺激素（m-PTH）、碱性磷酸酶（ALP）、Ca和磷水平。老年组初次给药前血清BGP水平为4.63±1.8 ng/ml，年轻组为4.33±0.92 ng/ml，两组间无显著差异。两组给药后24小时血清1,25（OH）2D水平均略有升高。老年组初次给药1周后血清BGP水平显著升高至11.5±3.0 ng/ml，升高约250%，且在给药开始后3周内一直维持升高。然而，年轻组血清BGP水平无变化。老年组给药前血清m-PTH水平为544±257 pg/ml，几乎达到正常上限，给药后略有下降。给药后血清ALP水平也略有下降，血清Ca水平略有升高，但变化均在正常范围内。我们得出结论，维生素D缺乏的老年受试者短期服用活性维生素D3后成骨细胞功能被激活。
