Final answer:
Aldosterone's mechanism of action is via an intracellular receptor, leading to gene transcription for proteins that regulate sodium reabsorption and potassium excretion, in turn affecting blood pressure and volume.
Step-by-step explanation:
The probable mechanism of action of aldosterone, a steroid hormone that regulates the reabsorption of sodium ions in the kidney tubular cells, is through an intracellular receptor. Since aldosterone is a steroid hormone, it can pass through the lipid bilayer of cell membranes and bind to receptors inside the cell. This binding leads to the transcription of specific genes, which in turn produce proteins that increase sodium reabsorption and potassium excretion.
Aldosterone also helps to regulate blood pressure and blood volume by ensuring that sodium is reabsorbed efficiently in the kidneys, saving water in the process. The consequential effect of aldosterone manifests in maintaining balance in water levels, blood pressure, and plasma potassium concentration. In the absence of aldosterone, as in Addison's disease, significant loss of sodium and an increase in plasma potassium can have dangerous health consequences.