Locatto M E, Fernandez M C, Caferra D A, Gimenez M C, Vidal M C, Puche R C
Calcif Tissue Int. 1984 Sep;36(5):604-7. doi: 10.1007/BF02405374.
The daily administration of supraphysiological doses of 1,25 dihydroxycholecalciferol (0.1-2.5 micrograms/d/100 g body weight) to rats, produced respiratory alkalosis. With the doses of 0.1-0.2 micrograms/d/100 g and feeding a diet with 0.7% of calcium, calcemias did not exceed 2.75 mM, and significantly reduced plasma ionized calcium levels were measured. The latter phenomenon was found associated with increased urinary excretion of cAMP, soft tissue calcium content, and polyuria with hypostenuria, all known effects of parathyroid hormone. These effects were absent in thyroparathyroidectomized rats treated in the same fashion. Present results suggest that the stimulus of low levels of plasma ionized calcium overcomes the probably inhibitory effect of the steroid on parathyroid hormone secretion.
给大鼠每日给予超生理剂量的1,25 - 二羟胆钙化醇（0.1 - 2.5微克/天/100克体重）会导致呼吸性碱中毒。给予0.1 - 0.2微克/天/100克的剂量并喂食含钙0.7%的饮食时，血钙水平不超过2.75毫摩尔，且测得血浆离子钙水平显著降低。发现后一种现象与环磷酸腺苷（cAMP）尿排泄增加、软组织钙含量增加以及多尿伴低比重尿有关，这些都是甲状旁腺激素的已知作用。以同样方式处理的甲状腺甲状旁腺切除大鼠未出现这些效应。目前的结果表明，低水平血浆离子钙的刺激克服了该类固醇对甲状旁腺激素分泌可能的抑制作用。
