What is the Origin of Progesterone Natriuresis?

The term is a compound of 'Progesterone,' the key hormone of the luteal phase and pregnancy, and 'natriuresis,' derived from the Latin 'natrium' (sodium) and Greek 'ouresis' (urination). Its origin as a recognized phenomenon stems from clinical observations that Progesterone administration provokes increased sodium excretion. This finding provided an important piece of the puzzle in understanding the complex hormonal control of blood pressure and fluid volume.

What is the Mechanism of Progesterone Natriuresis?

Progesterone acts as a competitive antagonist to Aldosterone, the primary mineralocorticoid, at the mineralocorticoid receptors (MR) located in the distal renal tubules of the kidney. Aldosterone normally promotes sodium reabsorption and potassium excretion. By binding to the MR without fully activating it, Progesterone blocks Aldosterone's ability to retain sodium, leading to increased sodium (and water) excretion. This natriuretic effect subsequently triggers a compensatory increase in the renin-angiotensin-aldosterone system, a feedback loop designed to prevent excessive sodium loss.

Progesterone Natriuresis ∞ Area

Progesterone Natriuresis

Meaning

Progesterone Natriuresis is the physiological process where the steroid hormone Progesterone induces an increase in the excretion of sodium and chloride ions in the urine, thereby acting as a natural diuretic. This effect is a direct consequence of Progesterone’s structural similarity to other mineralocorticoids, which allows it to modulate renal function. This mechanism contributes to fluid balance regulation, particularly during the luteal phase of the menstrual cycle and throughout pregnancy.