Hyperaldosteronism- Carroll

Question 1

When is renin released?

What does renin do?

What acts as negative feedback for renin?

Answer 1

Renin is released when there is a decrease in blood pressure (IE hemorrhage, dehydration, sodium deplation)

Renin converts angiotensinogen into angiotensin I

Angiotensin II negatively feedbacks to renin

Question 2

What two roles does angiotensin II have?

What activates angiotensin II?

Answer 2

1. Vasoconstricts vascular smooth muscle
2. Stimulates the adrenal gland to release aldosterone

Angiotensin Converting Enzyme (ACE)

Question 3

What does aldosterone do?

Where does it act?

Answer 3

Aldosterone upregulates apical sodium channels and basolateral Na/K pumps to conserve sodium and excrete hydrogen and potassium

Collecting duct of the nephron

Question 4

What are four classes of drugs that affect the RAAS pathway?

Give a drug for each class

Answer 4

1. Direct Renin inhibitors
   
   • Aliskiren
2. ACE inhibitors
   
   • Lisinopril, Captopril, Enalapril
3. Angiotensin Receptor Blockers
   
   • Losartan
4. Mineralocorticoid Receptor Antagonist
   
   • Spironolactone

Question 5

What is the etiology behind primary hyperaldosteronism?

What symptoms/clinical signs are seen?

Answer 5

The adrenal gland overproduces aldosterone, due to some sort of overgrowth (cancer, hyperplasia, etc)

• Hypertension younger than 30
• Hypertension greater than 160/100
• Hypertension with hypokalemia
• Resistant hypertension

Question 6

What are the initial tests for primary hyperaldosteronism?

What are the confirmatory tests?

Answer 6

Initial Tests

• Plasma Aldosterone Concentration >15ng/dL
• Plasma Renin Activity <1.0 ng/mL/h
• PAC:PRA >20

Confirmatory Tests

• Imaging of Adrenal glands
• Bilateral renal vein sampling

Question 7

What can cause primary hyperaldosteronism?

What can cause secondary hyperaldosteronism?

Answer 7

Primary hyperaldosteronism

• adrenocortical adenoma
• zona glomerulosa bilateral hyperplasia

Secondary hyperaldosteronism

• Renal Ischemia
• Chronic Diuretic/Laxative Use
• Hypoproteinemia
• Renal failure
• Heart failure

Question 8

What should be done if a unilateral mass is found on the adrenals of a patient with hyperaldosteronism?

What should be done if both adrenals are found to be overproducing aldosteronism?

Answer 8

Adrenalectomy

Medical management (IE spironolactone, eplerenone)

Question 9

What are two genetic disorders that might produce similar symptoms as primary hyperaldosteronism?

What causes the pathology?

Answer 9

11-Beta hydroxysteroid dehydrogenase type 2

• Lack of 11B-HSD2 causes a build-up of cortisol
• Cortisol can activate the mineralocorticoid receptor

Liddle’s Syndrome

• mutations in the ENaC channel cause it to be constitutively active
• potassium waste