Ng L L, Evans D J, Burke C W
Radcliffe Infirmary, Oxford, UK.
Clin Endocrinol (Oxf). 1987 Aug;27(2):235-43. doi: 10.1111/j.1365-2265.1987.tb01149.x.
In view of the known effects of cortisol and related compounds on sodium balance, we examined leucocyte 22Na+ efflux in patients with adrenocortical insufficiency. The ouabain-sensitive 22Na+ efflux rate constant, which reflects sodium pump activity, was lowered in secondary hypoadrenalism (mean 1.95 +/- SD 0.25 vs 2.33 +/- 0.45 h-1, P less than 0.002, n = 6). Patients with hypoadrenalism also had higher intracellular sodium content (mean 34.9 +/- SD 3.5 vs 27.8 +/- 9.5 mmol/kg dry weight, P less than 0.008) and lower intracellular potassium to sodium ratios (mean 9.7 +/- SD 0.7 vs 12.9 +/- 3.6, P less than 0.001). These defects in cellular sodium balance were corrected following replacement therapy with cortisol, prednisolone or dexamethasone. In-vitro incubation of normal leucocytes with 5-20 nmol/l dexamethasone led to an increase in the Na+/K+-ATPase activity. The effect of cortisol and related compounds on the distribution of sodium between intra- and extra-cellular fluid may be mediated by their action on the sodium pump.
鉴于皮质醇及相关化合物对钠平衡的已知作用，我们检测了肾上腺皮质功能不全患者白细胞的22Na+流出情况。反映钠泵活性的哇巴因敏感的22Na+流出速率常数在继发性肾上腺功能减退患者中降低（平均值1.95±标准差0.25对2.33±0.45 h-1，P<0.002，n = 6）。肾上腺功能减退患者的细胞内钠含量也较高（平均值34.9±标准差3.5对27.8±9.5 mmol/kg干重，P<0.008），细胞内钾钠比更低（平均值9.7±标准差0.7对12.9±3.6，P<0.001）。在用皮质醇、泼尼松龙或地塞米松替代治疗后，这些细胞钠平衡缺陷得到纠正。将正常白细胞与5 - 20 nmol/l地塞米松进行体外孵育会导致Na+/K+-ATP酶活性增加。皮质醇及相关化合物对细胞内液和细胞外液之间钠分布的影响可能是通过它们对钠泵的作用介导的。
