Aldosterone stimulates
sodium reabsorption by the
cortical collecting ducts in the
kidneys. When present, approximately
all of the sodium is reabsorbed, maintining
blood pressure. A
low sodium diet or
loss of sodium in large amounts can stimulate
secretion of aldosterone, via
angiotensin II.
The entire system is sometimes called the
renin angiotensin aldosterone system.
Aldosterone is also related to
potassium regulation, as mentioned above. Increased
plasma potassium directly stimulates the
adrenal glands to produce
aldosterone and release it into the
blood stream. This causes increased
potassium secretion in parallel with
sodium reabsorption, via
Sodium-Potassium ATPase in the
cortical collecting ducts of the
nephrons in the
kidneys.
Aldosterone also aids in
acclimatization to warm
climates by reducing sodium lost via an increase in reabsorption in the sweat glands.
Aldosterone is released during
stress to help retain water and sodium in the body, in case of
hemmorhage or
sweating.
These are my interpretation of my lecture notes, but I may have used some references from Hole's Anatomy and Physiology (Shier, Butler, Lewis) and Human Physiology (Vander, Sherman, Luciano)