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A 50-year-old African American male presents to your clinic with a 10-year history of hypertension. Each of his two kidneys has one renal artery. One renal artery is shown, by angiography, to have 80% stenosis. The other renal artery is completely normal. His electrolytes are also normal. Which of the following scenarios best conforms with these findings?

A. ADH levels will increase

B. The plasma renin activity is suppressed because of the high blood pressure

C. The serum potassium concentration is elevated because of potassium retention by the kidney with narrowed renal artery

D. Sodium excretion by the contralateral (nonstenotic) kidney is increased

E. Sodium excretion by the ipsilateral (stenotic) kidney is increased




its D.
i guess its bec stenosis of the artery leads to activation of RAA system of ipsilat kidney,and thus inc Na absorption by ipsilat to compensate for this,the contralateral kidney allows more Na loss.
do correct me please if i am wrong.


yep since the normal kidney has to work twice to compensate for the stenosed one .


excellent and great explanation !!!! thanks a lot anne... smiling face


How about A as answer. This is a case of high renin hypertension due to stenosed renal artery. Activated RAA system will lead to high AII levels which causes release of ADH from posterior pituitary.
Correct me if I am wrong please.


but how could Angiotensin-II directly stimulate ADH?it has a direct effect on Aldosterone(as far as i know).


yes anne,
ang-2 stimulates ADH release...i was thinking of A as ans becos... in renal artery stenosis...R-A-A axis stimulated and aldosterone increases sodium retention in both kidneys(endocrine action)...if it will be compensated by other kidney then U/L renal artery stenosis cases won't have hypertension at all :?


AII stimulates ADH release from posterior pituitary - I read it in First aid. Renal Physiology chapter.


thanx all for correcting me.


anne ,

Then whats the correct answer ?? I think i have seen this Q in Q bank..was that from it / other source ?

Do explain it anne :roll: iam all confused .Thanks


decreased renal artery diameter-->decreased arterial pressure with in kidneys-->decreased GFR and Pg(hyderostatic pressure in glomeruli)-->increased renin and increased angiotensin II-->compensation is constriction of efferent arterioles--->increased glomerular hydrostatic pressure and increase GFR.

:roll: thats what i can remember


asma i found this question in blackwell online questions,with the answer given as D,so i thought of a probable explanation to it :?

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