Role of osteocalcin in the calcium metabolism disorder

钙稳态是由甲状旁腺激素、降钙素和1.25(OH)2D3相互作用控制的。结果，体内血钙水平维持在10mg%左右。除了这些激素外，一些内源性因子（糖皮质激素、胃泌素、组胺、CGRP）也被报道具有低钙效力，许多药物已被用于临床和动物实验中治疗恶性肿瘤引起的高钙血症。一些作用于中枢神经系统的药物也会在实验动物身上产生低钙血症。阿司匹林被认为是最常用的止痛抗炎药。我们在多种病理生理条件下（空腹、甲状旁腺切除术、肾上腺切除术等）详细检查了阿司匹林引起的低钙血症。我们认为其作用机制不是由抑制肠道钙吸收引起的，而是由骨内膜细胞的功能紊乱引起的。骨钙素（ostecalcin， OC）是成骨细胞生成的骨适性有机基质。我们尝试测定血液中的OC和OC段。现在我们可以用我们的方法来做。除此之外，我们还试图检测血液中的离子钙。我们在乙醚麻醉下通过眼眶穿刺取了血样。在这一步中，我们已经知道乙醚麻醉会影响离子钙水平，特别是在重麻醉条件下。在实验过程中，我们可以建立许多有用的方法，用于进一步的实验。然而，要了解OC在骨代谢中的作用，还需要更多的研究。

Calcium homeostasis is controlled by the interactions of parathyroid-hormone, calcitonin and 1.25(OH)2D3. As a result, the blood calcium level is maintained about 10mg% in vivo. In addition to those hormones, several endogenous factors (glucocorticoid, gastrin, histamine, CGRP) also have been reported to have hypocalcemic potency and a number of agents have been used for the treatment of malignancy-induced hypercalcemia both clinically and in animal experiments. Several drugs acting on the central nerveous system can produce hypocalcemia in experimental animals, too. Aspirin has been treated as the most frequently used analgesic-antiinflammatory agent. We examined in detail the aspirin-induced hypocalcemia under many pathophysiological conditions (fasting, thyroparathyroid-ectomy, adrenalectomy, etc. We've thought that the mechanism of action would be induced by not the inhibition of calcium absorption from the intestinal tract but the functional disorder of bone lining cells. Osteocalcin (OC) is the bone proper organic matrix made by osteoblast. We tried to determine OC and OC segment in blood. Now we can do it by our method. In addition to it, we tried to detect the ionized calcium in blood. We took the blood sample by the orbital puncture under ether anethesia. In this step, we've known that ether anesthesia affects the ionized calcium level, especially under the heavy anesthetic condition. During the experiment, we could established many useful methods to use for further experiments. More works are necessary, however, to see the role of OC on the bone metabolism.