minéralocorticoids

Mineralocorticoids are a group of steroid hormones produced by the adrenal cortex. Their primary function is to regulate electrolyte balance, particularly sodium and potassium levels, in the body. Aldosterone is the most significant and potent mineralocorticoid. These hormones play a crucial role in maintaining blood pressure and fluid volume.

The production of mineralocorticoids is largely controlled by the renin-angiotensin-aldosterone system (RAAS). When blood pressure or blood volume drops, the kidneys release renin, which triggers a cascade of reactions leading to the synthesis of angiotensin II. Angiotensin II then stimulates the adrenal cortex to release aldosterone. Aldosterone acts on the distal tubules and collecting ducts of the kidneys, promoting the reabsorption of sodium ions and water, and the excretion of potassium ions. This action helps to increase blood volume and consequently blood pressure.

Besides aldosterone, other less potent mineralocorticoids exist, such as deoxycorticosterone. These hormones are essential for life, as deficiencies can lead to severe dehydration, low blood pressure, and electrolyte imbalances. Conversely, excessive production, as seen in conditions like hyperaldosteronism, can result in high blood pressure, fluid retention, and low potassium levels. Mineralocorticoid activity can also be influenced by other hormones, including ACTH and ADH, although RAAS is the primary regulator. Their influence extends beyond the kidneys to other tissues, albeit to a lesser extent.