Aldosteronas (UW) Flashcards
What type substance is aldosterone?
mineralcorticoid hormone
site of aldosterone production?
zona glomerulora in adrenal cortex
What pressure changes activate a release of aldosterone?
decr. blood pressure and decr. renal blood flow.
decr. blood pressure and decr. renal blood flow. Release of aldosterone. What is activated then?
ATII
What other conditions can increase release of aldosterone?
High serum potassium and increased ACTH levels (transient effect)
Mechanism of aldosterone?
increases number of basolateral Na/K ATPase pumps and apical Na channels in principal cells in cortical collecting ducts
Site of action of aldosterone?
Principal cells in cortical collecting ducts
Effect of aldosterone?
incr. Na and H20 reabsorption
due to aldosterone incr. Na and H20 reabsorption. What effect on K and H?
promotes K and H secretion
What cells secrete K?
principal
What cells secrete H?
intercalated
Aldosterone receptor antagonist effect on K and H?
Decrease secretion by collecting tubules
What does vasopresin on urea?
increase number of cell surface urea transporters in medullary collecting tubules . Results in increased urea reabsorption
Aldosterone secreting tumor. What disease?
Primary hyperaldosteronism (Conn’s syndrome)
Conn’s syndrome presentation?
Hypertension, hypokalemia, metabolic alkalosis (in collecting tubules loss of H), decreased RAAS activity.
treatment of unilateral adenoma?
surgical resection or medical therapy with aldosterone antagonists.
The most common agent (first-line) used for the treatment of unilateral adenoma?
spironolactone
If spironolactone is not tolerated what to use?
eplerenone (new agent for adenoma)
What type of acidosis cause HYPOaldosteronism?
Type IV renal tubular acidosis
