• Endocrine control of sodium balance by adrenal cortex and mineralocorticoids governs renal Na handling and body sodium homeostasis, demonstrated by adrenal regulation of Na excretion and aldosterone responses to Na status across humans and animals [1], [2], [4], [5], [7], [17], [14], [13].

• Active transport and tubular mechanisms underpin sodium homeostasis; classic work shows active sodium transport as a source of bioelectric current in frog skin with its inhibition, complemented by renal excretion studies detailing Na, K, and water handling [3], [18], [20].

• Hormonal signaling and quantification of sodium-retaining factors: the discovery and assay of desoxycorticosteroid/mineralocorticoid-like substances and urinary sodium-retaining corticoids, including methodological approaches to assay and characterize their activity [17], [7], [5], [16], [14].

• Interplay between adrenal endocrinology and cardiovascular/volume status: adrenal cortex factors influence hydration status and hypertension risk, connecting endocrine regulation to blood pressure and edema phenomena [8], [4], [1], [13].