Lindgren U, DeLuca H F
Calcif Tissue Int. 1982 Sep;34(5):510-4. doi: 10.1007/BF02411294.
The effect of ovarian insufficiency on calcium metabolism has been thought to involve an increased bone resorptive effect of parathyroid hormone and possible impaired synthesis of 1,25-dihydroxyvitamin D3. In the present study a rat model allowing for controlled serum levels of parathyroid hormone and 1,25-dihydroxyvitamin D3 was used. Oophorectomy in this species is associated with increased serum levels of 1,25-dihydroxyvitamin D3 and decreased bone mass. Although thyroparathyroidectomy increased bone mass, an increased sensitivity of bone to parathyroid hormone in oophorectomized rats was not observed. Thus the development of the osteopenia did not seem to be related to increased parathyroid hormone sensitivity or to reduced levels of 1,25-dihydroxyvitamin D3. Exogenous 1,25-dihydroxyvitamin D3 increased bone mass in oophorectomized as well as intact rats. Intestinal calcium transport was increased by moderate doses of 1,25-dihydroxyvitamin D3. Intestinal calcium transport was also reduced by thyroparathyroidectomy and increased by the administration of parathyroid extract. A tendency for increased accumulation of 1,25-dihydroxyvitamin D3 in blood in oophorectomized rats has been noted. It is suggested that the tendency to hypercalcemia in ovarian-insufficient females given 1-hydroxylated vitamin D compounds may be related to a diminished metabolism of 1,25-dihydroxyvitamin D3.
卵巢功能不全对钙代谢的影响被认为涉及甲状旁腺激素的骨吸收作用增强以及1,25 - 二羟维生素D3的合成可能受损。在本研究中，使用了一种能控制甲状旁腺激素和1,25 - 二羟维生素D3血清水平的大鼠模型。该物种的卵巢切除术与血清1,25 - 二羟维生素D3水平升高和骨量减少有关。虽然甲状旁腺切除术增加了骨量，但未观察到卵巢切除大鼠的骨对甲状旁腺激素的敏感性增加。因此，骨质减少的发生似乎与甲状旁腺激素敏感性增加或1,25 - 二羟维生素D3水平降低无关。外源性1,25 - 二羟维生素D3增加了卵巢切除大鼠和完整大鼠的骨量。中等剂量的1,25 - 二羟维生素D3可增加肠道钙转运。甲状旁腺切除术也会降低肠道钙转运，而给予甲状旁腺提取物则会增加肠道钙转运。已注意到卵巢切除大鼠血液中1,25 - 二羟维生素D3的积累有增加的趋势。有人提出，给予1 - 羟化维生素D化合物的卵巢功能不全女性出现高钙血症的倾向可能与1,25 - 二羟维生素D3的代谢减弱有关。
