Adrenal III Flashcards
clinical features of cushing’s syndrome
incr. growth of fat deposits on face, trunk, and neck
catabolic effects on muscle cause wasting and myopathy
arrest of linear growth occurs in childhood Cushing’s
catabolic effects on skin cause atrophy and easy bruising and striae
lab findings in Cushings
loss of diurnal rhythm of cortisol secretion, incr. urinary excretion of cortisol and metabolites, insulin resistance and hyperglycemia, potassium wasting causing hypokalemia
causes of Cushing’s syndrome
iatrochenic, Cushing’s disease (pituitary corticotroph neoplasms causing high ACTH), ectopic ACTH production by tumors, esp. small cell carcinoma of the lung, and adrenal corticol tumors (ACTH independent)
Dx of Cushing’s syndrome
you need to show hypercortisolemia
meausre with salivary cortisols at midnight
then, establish ACTH dependence or independence. If it is dependent, look for a pituitary tumor.
look at regulatory system to distinguish ACTH excess from non-pituitary tumors
Tx of cushing’s syndrome
pituitary surgery for cushing’s disease
steroidogenic inhibitors as a temporary measure while you figure things out
adrenalectomy if you can’t find a causative tumor
excision of non-pituitary ACTH-producing tumors
What are the state of mineralocorticod excess?
pirmary aldosteronism, like adrenal adenomas/hyperplasia
glucocorticoid suppressible hyperaldosterone
hypertensive forms of congential adrenal hyperplasia
syndrome of apparent mineralocorticoid excess
Tx of primary hyperaldosteronism
surgery to remove aldosterone producing tumors
medical management with mineralocorticoid receptor antagonists like spironolactone or eplerenone.
spironolactone is more effective but is unpopular with men because of its anti-androgen effects
What is glucocorticoid remediable aldosteronism?
a hypermineralocorticoid that aresponds to glucocorticoids
normally, glucocoritoid productio driven by ACTH
mineralocorticoid production driven my renin and K
in this case, you get a translocation of the glucocorticoid promoter (driven by ACTH) onto the mineralocorticoid (aldo) gene
now, aldo is sensitive to ACTH (which is senstive to cortisol levels). often cyclic
overall, this causes too much aldo and can cause HTN
tx fo glucocorticoid remediable aldosteronism?
glucocorticoids like dexamethasone to lower ACTH and reduce production of aldo
clincial manifestationsof remediable aldosteronism
salt and fluid retention with HTN
low renin and normal K (because the disease is not as severe)
autosomal dominant
incr. risk of hemorrhagic stroke in family
What is CYP11B1 hydroxylase deficiency? What are the clinical and lab symptoms
CYP11B1 is the last enzyme in cortisol synthesis.
these patients have partial adrenal insufficiency with low cortisol levels
ACTH promotes corticol hyperplasia
high ACTH leads to increased DOC producition in the zona fasciculata (DOC is the immediate precursor to cortisol_
DOC is a potent mineralocorticoid: SALT RETENTION, K LOSS, HTN
aldo is low
ACTH also drives androgen production- virulization and precocious puberty with high 17OH prgogesterone
Tx of CYP11B1 hydroxylase
low dose glucocorticoids- prevents adrenal crisis and lowers DOC production
Syndrome of apparent mineralocorticoid excess
condition where the inactivation of cortisol to cortisone by 11beta HS dehydrogenase enzyme is not working (either a genetic problem or a problem due to excess licorice consumption).
high cortisol cross-reacts with the mineralocorticoid receptors, causing salt retention, K wasting, and hypertension
Treatment of syndrome of apparent mineralocorticoid excess
dexamethasone. does not cross react with mineralocorticoid receptors but will suppress cortisol production
What are catecholamine secreting tumors of the adrenal medulla? location, causes, general types of symptoms
pheochromocytomas: catecholamine secreting tumors of chromaffin neuroendocrine cells
90% in adrenal medulla; 10% outside of adrenal medulla
may be hereditary or sporatic
symptoms are those of adrendergic stimulation
