Premium
THE HUMAN LEUCOCYTE SODIUM PUMP IN CUSHING'S SYNDROME
Author(s) -
NG L. L.,
EVANS D. J.,
BURKE C. W.
Publication year - 1988
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.1988.tb03660.x
Subject(s) - endocrinology , medicine , sodium , aldosterone , efflux , adrenalectomy , chemistry , extracellular fluid , potassium , cushing syndrome , supine position , extracellular , biochemistry , organic chemistry
SUMMARY Because corticosteroids have important effects on sodium homeostasis, we studied leucocyte 22 Na efflux in patients with Cushing's syndrome. The ouabain‐sensitive 22 Na + efflux rate constant was raised in Cushing's syndrome (mean ± SD 2.84 ± 0.32 vs 2.35 ± 0.53/h, P < 0.001, n = 15). This efflux rate constant correlated with the urinary free cortisol ( r s = 0.61, P < 0.02), but less significantly with the 0900 h plasma cortisol ( r s =0.46, P <0.08). There was no correlation with the supine plasma aldosterone. Intracellular sodium content was significantly lower in Cushing's syndrome (21.1 ± 4.6 vs 27.8 ± 9.5 mmol/kg dry weight, P < 0.01), with a raised intracellular potassium to sodium content ratio (16.1 ± 3.3 vs 12.9 ± 3.6, P < 0.01). After treatment of the Cushing's syndrome by trans‐sphenoidal adenomectomy or adrenalectomy, these defects in cellular sodium balance were corrected. Thus, the distribution of sodium between intra‐ and extracellular fluid may be affected by adrenal corticosteroids via an action on the sodium pump.