The Action of Cortisone and Desoxycorticosterone Acetate on Glomerular Filtration Rate and Sodium and Water Exchange in the Adrenalectomized Dog

Importance of sodium intake and mineralocorticoid hormone in the impaired water excretion in adrenal insufficiency

“…The results of the present investigation must be considered on the background of the previous suggestions that the impaired renal diluting capacity characteristic of adrenal insufficiency is due to glucocorticoid deficiency and is mediated either by sustained release of ADH (9, 10) or by a failure to achieve maximal impermeability to water of the distal nephron (3)(4)(5)(6)(7)(8). Of primary importance is the fact that the duration of glucocorticoid withdrawal in most previous studies has been in excess of the period of glucocorticoid deficiency in the present studies.…”

“…The importance of sodium balance in the capacity of the adrenalectomized dog to excrete water was not only indicated by the acute water-loading studies but also by (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13).' In an effort to avoid any secondary effects related to negative sodium balance and depletion of extracellular fluid volume, the initial group of studies were performed while the animals were offered a high sodium intake as saline drinking water.…”

“…Many investigators (1-13) have suggested that the presence of glucocorticoid hormone is necessary for normal renal diluting capacity. This importance of glucocorticoid hormone has been proposed by some authors to be related to a direct action of the hormone on the water permeability of the tubular epithelium of the collecting duct (3)(4)(5)(6)(7)(8), while other authors have suggested that the presence of glucocorticoid hormone is necesary for the maximal suppression of vasopressin release (9-11). The present results do not support either of these hypotheses, since in the presence of a high intake of sodium, glucocorticoid hormone was not necessary for a normal response to the water load.…”

“…There is considerable evidence that adrenal insufficiency is associated with an impaired ability to attain a normal water diuresis (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13). The mechanisms involved in this impairment of water excretion have not been clearly elucidated, however, two possible mechanisms have been proposed.…”

“…The mechanisms involved in this impairment of water excretion have not been clearly elucidated, however, two possible mechanisms have been proposed. One (3)(4)(5)(6)(7)(8) is that, although the release of antidiuretic hormone (ADH)' from the hypothalamus in adrenal insufficiency is normally suppressed during water loading, the water impermeability of the distal nephron is incomplete in the absence of glucocorticoid hormone. In contrast, other authors (9)(10)(11) have suggested that the release of ADH is not suppressed normally during water loading in the presence of adrenal insufficiency and increased circulating levels of ADH account for the inability to excrete water normally.…”