stenotic kidney increases renin leading to salt and water retention, contralateral kidney decreases renin leading to salt and water excretion
stage 2 renovascular HTN
Aldosterone increases (1), leading to increased volume (which also increases blood pressure).
1. sodium reabsorption
The blood vessel problem in the affected kidney can be treated surgically, and (1) is reversible if identified before there is too much damage to the kidney with the stenotic blood vessel.
1. fibromuscular dysplasia
Children with renovascular hypertension may have (1) (not a malignant type).
1. fibromuscular dysplasia
The kidney secretes renin based on the amount of (1) determined by the (2) in the nephron.
1. blood flow (tubular sodium concentration actually) 2. juxtaglomerular apparatus
AT II can also lead to contraction of the (1) which decreases the glomerular surface area, producing (2)
1. smooth muscle in mesangial cells 2. less filtration.
•AngII effects vary in normal vs ischemic kidney:
•Good kidney: ↓BP activates _____
•Ischemic kidney: reduced afferent blood flow ____ (particularly if on ACE inhibitors ⇒ contraindicated for renovascular stenosis)
renin-AT --> ↑GFR ;
hypertension leads to renal hypo perfusion of kidneys
stage 3 renovascular HTN
Histologically, in (3) the affected kidney is smaller, and tubules show (1) without much (2)
3. fibromuscular dysplasia 1. ischemic atrophy 2. interstitial fibrosis
Fibromuscular dysplasia involves thickening of the (1) which alternates with (2) produces an arteriogram showing a (3) pattern.
1. medial arterial smooth muscle 2. atrophy 3. “string of beads”
“string of beads” pattern on arteriogram
Renin catalyzes the conversion of (1) to (2)
1. angiotensinogen to 2. angiotensin I.
Examination of the stenotic or occluded renal artery shows (1) most of the time, and the disease is most common in men over 50.
One can directly show in these patients that renal vein (1) is increased in the ischemic (poor blood flow) kidney but normal in the contralateral one.
Angiotensin II (AT II) also leads to production and release of (1) which can (2)
1. prostaglandins and nitric oxide 2. dilate the afferent arteriole.
increased renin within kidney with stenosis leading to increased serum renin and hypertension
stage 1 renovascular HTN
Angiotensin II has a greater vasoconstriction of the (1) arteriole which can lead to (2) in some circumstances, such as (3)
1. efferent 2. increased filtration 3. early diabetic nephropathy (stage I)
Occasionally, renal artery vasculitis, (such as (1), can cause (2) in children or less commonly in adults.
1. Takayasu’s or giant cell arteritis which affect larger vessels 2. fibromuscular dysplasia
Goldblatt blocked one renal artery in a rat and then showed that (1) were increased in the nephrons and venous return from that kidney whereas they were normal in the other kidney
1. renin, angiotensin II, and aldosterone
Renovascular hypertension has three basic stages. The first stage has increased (1) within the kidney with the stenotic blood vessel which leads to (2).
1. renin 2. systemic hyperreninemia (increased serum renin) and hypertension
In the second stage of renovascular hypertension, the two kidneys have opposing functions: the stenotic kidney has increased (1) and (2) sodium and water; the contralateral non-stenotic kidney (3) sodium and water, and has decreased (1) production.
1. renin 2. retains 3. excretes
Because renal function in renovascular hypertension is highly dependent on renin and angiotensin II effects, the use of (1) in patients with renovascular stenosis can be complex or even counterproductive.
1. ACE inhibitors
(1) cells have (2) which converts angiotensin I to angiotensin II, which has powerful vaso-constrictive actions and increased production of (3)
1. Pulmonary and renal endothelial 2. ACE (angiotensin converting enzyme) 3. aldosterone
If the (1) is restored to the stenotic kidney during the first two stages of renovascular HTN, then the blood pressure will be normalized, so this is curable hypertension.
1. blood flow
In the third stage of renovascular HTN, the hypertension leads to (2) of both kidneys and produces further renal damage.
2. renal hypoperfusion
•Atherosclerotic plaques (embolisms from atherosclerosis within abdominal aortic aneurysms) block aortic ostia or narrow the renal artery lumen.
Atheroembolism may be spontaneous or initiated by trauma; can spread to as far as glomerular capillaries and may cause ____
acute renal failure
Clinically, (1) can be heard over the stenotic renal artery because of the sound of the blood being pushed through the narrowing, but of course there would be no (1) with (2)
1. a bruit 2. complete stenosis
The resulting (1) of fibromuscular dysplasia can also damage the “unaffected” (non-stenotic one) contralateral kidney if the disease is not diagnosed for a long time because (1) causes narrowing and occlusion of blood vessels in the kidney. This can lead to bilateral disease and renal failure.
The (1) that forms within (2) can embolize into the renal arteries blocking the ostia or narrowing the artery (because of flow patterns it affects the (3) renal artery more than the (4). These stenotic lesions can be identified as embolic because they will have (5) (areas of clear space where the lipid is washed out in the tissue processing).
1. atherosclerosis 2. abdominal aortic aneurysms 3. left 4. right 5. cholesterol clefts