adrenal causes of hypertension Flashcards
What are the 3 layers of the cortex of the adrenal gland
Zona Glomerulosa- aldosterone Zona Fasciculata- cortisol Zona Reticularis- adrenal androgens pneumonic (GFR) then the medulla which makes catecholamines (adrenaline and noradrenaline etc)
What are some adrenal causes of hypertension
Primary hyperaldosteronism the issue in the zona glomerulosa can be due to: - adenoma - hyperplasia - genetic (Rare)
Phaeochromocytoma
-tumour of the adrenal medulla.
Outline the pathway for aldosterone secretion
Angiotensinogen is made by the liver and it converts into angiotensin 1 by renin (from the kidneys), which is converted into angiotensin 2 by ACE and Angiotensin 2 goes to the zona glomerulosa and stimulates aldosterone production (promotes reabsorption of salt and water).
Who do you screen for primary hyperaldosteronism
Hypokalaemic people,
resistant hypertension- inadequate control on 3 drugs, control on 4 drugs or more
younger people
What are some tests for primary hyperaldosteronism
Initial screening tests
- suppressed renin
- normal/ high aldosterone
confirmatory test
- oral or IV Na+ supression test
then do adrenal CT scan,
adrenal venous sampling
What is the treatment for primary hyperaldosteronism where there is unilateral adenoma
- Laparoscopic adrenalectomy
- medical treatment (sometimes)
What is the treatment for primary hyperaldosteronism where there is bilateral hyperplasia
medical treatment (aldosterone antagonists)
- spironolactone
- eplerinone
Outline Adrenaline secretion and the innervation to the adrenal medulla
The medulla is modified post-ganglionic nerve cells which are innervated by preganglionic nerves
Sympathetic neurones in the spinal cord innervate the medulla, ACH stimulates the medulla to make L-DOPA (from tyrosine) which makes dopamine that can go on to make noradrenaline and adrenaline
What are products of the adrenal medulla
Catecholamines
- dopamine
- noradrenaline—-> adrenaline (requires cortisol)
What are the biological effects of adrenaline
Vasoconstriction
Vasodilation in muscles
increased heart rate
sweating
What are the biological effects of noradrenaline
Vasoconstriction- increased BP, pallor
Glycogenolysis
What is a phaeochromocytoma (phaeo)
It is a tumour of the adrenal medulla.
How do Phaeos present
“Spells”
- headache, sweating
- pallor, palpitation
- anxiety
hypertension
-permanent or intermittent
family history
What are some genetic conditions associated with Phaeos
Neurofibromatosis type 1 (NF1)
Multiple endocrine neoplasia type 2 (MEN 2)
Von Hippel- Lindau syndrome
How would you biochemically diagnose a phaeo
24-hour urine
- normetanephrine and metanephrines
- 3 methoxytyromine
plasma
- noradrenaline and adrenaline
- metanephrines
