The most important mineralocorticoid regulator of electrolyte concentrations in extracellular fluids is most important mineralocorticoid regulator of electrolyte concentrations in extracellular fluids is

The most important mineralocorticoid regulator of electrolyte concentrations in extracellular fluids is Aldosterone.
Aldosterone hormone is produced by the adrenal gland, it acts in the functional unit of the kidneys to aid in the conservation of sodium, secretion of potassium, water retention and to stabilize blood pressure. The hormone causes water to be absorbed along with sodium ions which increases the blood volume and therefore blood pressure. It indirectly regulates blood levels of electrolytes and helps to maintain the blood pH. 

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