Mujais S K, Chekal M A, Lee S M, Katz A I
Pflugers Arch. 1984 Sep;402(1):48-51. doi: 10.1007/BF00584831.
Mineralo- and glucocorticoids stimulate renal Na-K-ATPase activity if given over a few days, but their immediate effect on the enzyme (i.e. within the time period required to alter electrolyte transport) remains controversial. We evaluated the short-term (3 h) in vivo effect of physiologic and pharmacologic doses of the natural glucocorticoid (corticosterone) and mineralocorticoid (aldosterone), and of a semisynthetic glucocorticoid (dexamethasone) on Na-K-ATPase activity in cortical collecting tubules microdissected from adrenalectomized rats. This nephron segment was chosen because it is a major target site for both classes of corticoids. Neither corticosterone (0.006, 0.6, and 5 mg/100 g body wt, IM), nor dexamethasone (5 mg/100 g body wt, IM) or aldosterone (10 micrograms and 50 micrograms, IV) altered significantly Na-K-ATPase activity in the cortical collecting tubule of these animals 3 h after administration. These results confirm our previous observations in the mouse, and suggest that the enhancing effect of corticosteroids on the renal enzyme seen after longer intervals represents a secondary phenomenon, possibly related to augmentation of the sodium load presented to the pump.
给予矿物ocorticoids和糖皮质激素数天会刺激肾钠钾ATP酶活性，但它们对该酶的即时作用（即在改变电解质转运所需的时间段内）仍存在争议。我们评估了生理剂量和药理剂量的天然糖皮质激素（皮质酮）、矿物ocorticoid（醛固酮）以及半合成糖皮质激素（地塞米松）对从肾上腺切除大鼠显微解剖的皮质集合管中钠钾ATP酶活性的短期（3小时）体内作用。选择这个肾单位节段是因为它是两类皮质激素的主要作用靶点。给予皮质酮（0.006、0.6和5毫克/100克体重，肌肉注射）、地塞米松（5毫克/100克体重，肌肉注射）或醛固酮（10微克和50微克，静脉注射）后3小时，这些动物皮质集合管中的钠钾ATP酶活性均未显著改变。这些结果证实了我们之前在小鼠中的观察结果，并表明皮质类固醇在较长时间后对肾酶的增强作用是一种继发现象，可能与泵所面对的钠负荷增加有关。
