Effect of sodium deprivation on plasma and adrenal concentrations of aldosterone and corticosterone in the Brattleboro homozygous rat.

Despite the great impairment in water balance occurring in the Brattleboro rat, homozygous for diabetes insipidus and lacking hypothalamic arginine-vasopressin, fed a normal sodium diet, the metabolic effects of a chronic sodium deprivation were similar in the Brattleboro rat and in the Long-Evans rat used as control. Concomitantly, whilst the plasma and adrenal concentrations of aldosterone were two fold lower in the Brattleboro rat than in the Long-Evans rat fed a normal diet, after ten days of sodium restriction they became similar in the two groups of rats; sodium deprivation greatly increased aldosterone production in the same order of magnitude both in the Brattleboro rat and in the Long-Evans rat. It is suggested that chronic sodium depletion might have, in the Brattleboro rat, either suppressed the cause of the reduced aldosterone secretion or induced mechanisms which have offset it.