Renal Flashcards
What converts angiotensin I → angiotensin II
angiotensin-converting enzyme (ACE) in the lungs converts angiotensin I → angiotensin II
What does Angiotensin do
causes vasoconstriction of vascular smooth muscle leading to raised blood pressure and vasoconstriction of efferent arteriole of the glomerulus → increased filtration fraction (FF) to preserve GFR. Remember that FF = GFR / renal plasma flow
stimulates thirst (via the hypothalamus)
stimulates aldosterone and ADH release
increases proximal tubule Na+/H+ activity
What does angiotensin II do?
Angiotensin II acts on the adrenal gland to stimulate the release of aldosterone
What does aldosterone do
Acts on kidneys to stimulate reabsorption of salt NaCl and H2O
What does renin do?
released by renal juxtaglomerular cells in response to reduced renal perfusion to hydrolyse angiotensinogen to form angiotensin I
(also secreted in response to hyponatraemia, sympathetic nerve stimulation)
Where does spironolactone act?
In the cortical collecting duct
What is the mechanism of action of Spironolactone?
aldosterone antagonist
What is the mechanism of action of furosemide?
Inhibits the Na-K-Cl cotransporter in the thick ascending limb of the loop of Henle
Adverse effects of Spironolactone?
-hyperkalaemia
-gynaecomastia (condition of overdevelopment or enlargement of the breast tissue in men or boys). Less common with eplerenone
Effect of NSAID therapy on kidney
decreased GFR, decreased renal plasma flow, no change in filtration fraction
Example of Angiotensin II receptor antagonist? (ARB)
candesartan
valsartan
losartan
olmesartan
What acid base imbalance would you expect following profuse vomiting
Metabolic alkalosis: Increased pH; Elevated CO2; Elevated HCO3-
