primary and secondary adrenal insufficiency

numbndumb · May 30, 2012

ok, this is smthing i just dont get! may be its too late at night for my brain to be functioning but anyway,

So i read in FA that in primary adrenal insufficiency, you have hyperkalemia but in secondary adrenal insufficiency(decreased ACTH frm the pituitary), there is NO hyperkalemia???

I mean dont you have no aldosterone in both cases? You DO need ACTH for the first step of adrenal steriods systhesis(i.e. desmolase converting cholesterol to pregnenalone) dont u?

Anyone's got this concept clear? please explain. thanks

Hope2Pass · May 30, 2012

Got this from a different thread. Good question btw.

Glomerulus said:
In primary adrenal insuff. the adrenals are the problem. Meaning all the hormones(Aldost,Cortisol, DHEA and Androgens) are deficient. This causes that there is a high ACTH secretion(causes Skin pigmentation since it is realesed with alpha-MSH) and the low Aldosteron is the cause of the hyperkalemia. In secondary adrenal insuff. the problem is at a pituitary level meaning that ACTH is low leading to a reduced stimulation of the Zona fasciculata and reticularis, where as the Zona glomerulosa is stimulated via Angiotensin and Potassium. Therefore Hyperkalemia is not presented cause Aldosteron secretion is still present. Is this explanation ok for you? Best of luck studying!

numbndumb · May 30, 2012

yeah thanks. and i just checked Kaplan too. So angiotensin 2 does stimulate via its receptor and 2nd messenger. hmmm, i HATE going back to the big books though. LOL

primary and secondary adrenal insufficiency

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