Hyperaldosteronism Flashcards
Specialised cells in afferent arteriole of kidney?
Juxtaglomerular cells
Role of juxtaglomerular cells?
Sense BP in these vessels, when it senses low BP they secrete renin hormone
What happens when juxtaglomerular cells secrete renin hormone?
Liver secretes protein called angiotensinogen
What happens to angiotensinogen?
Renin converts it to angiotensin 1
What happens to angiotensin 1?
ACE converts it to angiotensin II (lungs)
What is role of angiotensin II?
Stimulates release of aldosterone
What is aldosterone?
Mineralocorticoid
What does aldosterone act on?
The kidney
What does aldosterone cause to occur when it acts on kidney?
- Increased Na+ reabsorption form distal tubule
- Increased K+ secretion from distal tubule
- Increased H+ secretion from CDs
What is hyperaldosteronism AKA?
Conn’s syndrome
What is Conn’s syndrome?
When adrenal glands are directly responsible to producing too much aldosterone
What will serum renin be like in primary hyperaldosteronism?
LOW serum renin as suppressed by high BP, several possible reasons for this
Possible reasons for high BP causing Conn’s syndrome?
- Adrenal adenoma secreting aldosterone (common)
- Bilateral adrenal hyperplasia
- Familial hyperaldosteronism type 1 & type 2 (rare)
- Adrenal carcinoma (rare)
What is secondary hyperaldosteronism?
Where XSive renin stimulates adrenal glands to produce more aldosterone
Serum renin will be high
Causes of high renin levels?
Renal artery stenosis
Renal artery obstruction
Heart failure
What generally causes high renin levels?
When BP in kidneys is disproportionately lower than BP in rest of body
Investigations for hyperaldosteronism?
-Check renin & aldosterone levels & calculate a renin:aldosterone ratio
What does high aldosterone and low renin signify?
Primary hyperaldosteronism
What does high aldosterone and high renin signify?
Secondary hyperaldosteronism
Other investigations for aldosterone?
BP
Serum electrolytes (hypo K+)
Blood gas analysis (alkalosis)
Investigating for cause of high renin?
- CT or MRI
- Renal doppler US, CT angiogram or MPA
Management of hyperaldosteronism?
- Eplerenone
- Spironolactone
Treating underlying cause of hyperaldosteronism?
- Surgical removal of adenoma
- Percutaneous renal artery angioplasty via femoral artery to treat renal artery stenosis
Presnetation of hyperaldosteronim?
High blood pressure. Low level of potassium in the blood. Feeling tired all the time. Headache. Muscle weakness. Numbness
