hyperaldoseronism and pheochromocytoma

Question 1

RAAS System

Answer 1

Hemorrhage, dehydration, sodium depletion, heart failuru–> decrease in blood pressure–> Kidney senses it and makes RENIN

Liver is continuously making angiotensinogen

Renin converts angiotensinogen to angiotensin 1

ACE converts Angiotensin 1 to angiotensin 2 vasoconstriction of vascular smooth muscle
ANG2–> Aldosterone–> Renal water, and Na retention, potassium and H secretion in distal tubule

NA is exchanged for K and H

Question 2

Primary Hyperaldosteronism: Adrenal adenoma making

Answer 2

Increased adreneal secretion of Aldosterone–> Renal water and Na reterntion, Potassium and H Secretion–> Increased blood pressure, hypokalemia

Consider testing for primary aldosteronism for: hypertension and hypokalemia, resistant HTN, adrenal adenoma, HTN, HTN at a young age, severe HTN

Secondary HTN

Question 3

Diagnosing hyper aldosteronism

Answer 3

measure an increased ratio of plasma aldosterone to plasma aldosterone to plasma renin activity

Aldosterone increased due to autonomous secretion from an adrenal adenoma

Renin is suppressed bc of increased bp and increased sodium at the macula densa

MRA can not be perscribed if they have PHA testing

Question 4

Secondary hyperaldosteronism caused

Answer 4

Renal ischemia, decreased intravascular volume, CHF, chronic diuretic or laxative use, hypoproteinemic states (cirrhosis, nephrotic syndrome), Na wasting disorders, chronic renal failure

Renal ischemia increases renin secretion from JG cells, CHF increases renin secretion via baroreceptor reflex
Diuretic/laxatives increases renin because of Na and volume loss

Question 5

Pharmacology for primary aldosteronism

Answer 5

spironolactone and eplerenone

Question 6

The mineralocorticoid receptor in the renal tubule is protected from activation by cortisol by the enzyme 11 B hydroxysteroid dehydrogenase type 2 (11 B- HSD 2 )

Answer 6

Apperent mineralocorticoid excess- 11BHSDH2 deficiency

Liddle syndrome- mutations in the amiloride- sensitive epithelial sodium channel, treated with amiloride and triamterene (both potassium sparing diuretics)
vf

Question 7

Catecholamine syntheis

Answer 7

Tyrosine hydroxylase is generally considered to be the RLS

PNMT (converts NE-> epinephrine) is expressed in the adrenal medulla more than the sympathetic nerves so that NE is the primary product of the adrenal medulla

Question 8

Pheochromocytoma

Answer 8

tumors of the chromaffin cells of the adrenal medulla

Paragangliomas- tumors that arise from extra-adrenal ganglia of the sympathetic nervous system

Pheochromocytomas secrete excessive amounts of both Epi and NE

Para gangliomas and mets of pheochromocytomas typically secrete primarily NE

Question 9

Biochemical tests

Answer 9

catecholamines in the urine or free metanephrines in the plasma

imiaging after the cio chrm

MIBG nuclear medicine, radiation is taken up by the pheo,