Disorders of calcium metabolism

(1) Ellsworth-Howard试验标准：采用1-34人PHT建立Ellsworth-Howard试验标准。这些标准现在在日本被广泛使用。(2)假性甲状旁腺功能减退患者pth抵抗的研究：我们发现pth抵抗是由于缺乏1,25 <(OH)_2> <D_3>的作用，而1,25 <(OH)_2> <D_3>治疗假性甲状旁腺功能减退可控制钙代谢异常。(3)肌强直性营养不良、库欣综合征及恶性肿瘤患者钙代谢的临床研究：研究这些疾病的钙、磷酸盐代谢并进行治疗试验。(4) OPLL的钙代谢：缺乏1,25 <(OH)_2> <D_3>的作用可能参与了OPLL的恶化。(5)大鼠灌注平衡研究：我们阐明了维生素D促进钙的肾重吸收，维生素D增强甲状旁腺激素的作用。(6)降钙素的肾作用：发现降钙素的作用不依赖于cAMP，且受前列腺素<E_2>的影响。(7)磷剥夺的适应机制：利用链脲佐菌素诱导的糖尿病大鼠，我们证明胰岛素直接或间接参与了这种适应。此外，胰岛素可促进肾1 < α > -羟化酶的激活。(8)对成骨细胞样细胞的研究：发现基质囊泡膜中的磷脂酰丝氨酸形成Ca-PS-P复合物，可能在钙化的早期阶段起重要作用。(9) PTH基因的研究：确定了介导1,25 <(OH)_2> <D_3>作用的DNA区域。我们还可以确定PTH基因表达所必需的区域。

(1) Criteria of Ellsworth-Howard test: We established the criteria of Ellsworth-Howard test using 1-34 human PHT. These criteria are now widely used in Japan. (2) Investigation of PTH-resistance in peudohypoparathyroidism: We revealed that PTH-resistance is due to the lack of action of 1,25 <(OH)_2> <D_3> and application of 1,25 <(OH)_2> <D_3> to psedohypoparathyroidism :can control the abnormalities of calcium metabolism. (3) Clinical investigations of calcium metabolism in myotonic dystrophy, Cushing syndrome and malignancies: We investigated the calcium and phosphate metabolism in these diseases and carried out therapeutic trials. (4) Calcium metabolism in OPLL: It was revealed that the lack of 1,25 <(OH)_2> <D_3> action may participate in its exacerbation. (5) Perfusion balance studies in rat: We clarified renal reabsorption of calcium is facilitated by vitamin D and vitamin D enhances the action of PTH. (6) Renal action of calcitonin: It was revealed that calcitonin exerts its action independent of cAMP and is affected by prostaglandin <E_2> . (7) Adaptation mechanism of phosphorus deprivation: Using streptozotocin-induced diabetic rats, we demonstrated that insulin is directly or indirectly involved in this adaptation. In addition, the activation renal 1 <alpha> -hydroxylase is facilitated by insulin. (8) Studies on osteoblast-like cells: It was revealed that phosphatidylserine in matrix vesicle membrane forms Ca-PS-P complex, which may be important in the early step of calcification. (9) Studies on PTH gene: We identified the DNA area which mediates 1,25 <(OH)_2> <D_3> action. We could also identify the area which is necessary for PTH gene expression.