prostaglandins and renal function

Question 1

prostaglandin are a family of molecules formed

Answer 1

from the fatty acid arachidonic acid by the cyclooxyrgenase enzymes COX-1 AND COX-2

Question 2

Major prostaglandins synthesised by the kidney

Answer 2

• PGE2 by the medulla

- PGI2 by the glomeruli (prostacyclin)

Question 3

both PGE2 and PGI2

Answer 3

acts as vasodilators and are natriuretic and are synthesised in response to:

• ischaemia
• mechanical trauma
• angiotensin II
• bradykinin
• ADH

Question 4

under normal circumstances

Answer 4

prostaglandins have little effect upon renal blood flow or GFR but they are important under conditions of vasoconstriction or decreased effective arterial blood volume where they cause compensatory vasodilation

Question 5

prostaglandins affect GFR BY:

Answer 5

1. a direct vasodilatory affect on the afferent arteriole
2. releasing renin leading to increased levels of angiotensin II which causes vasoconstriction of the efferent arteriole which increases filtration pressure

Question 6

NSAIDS

Answer 6

INHIBIT COX ENZYMES AND CAN PRECIPITATE AN AKI BY DECREASING THE GFR IN CONDITION WHERE RENAL BLOOD FLOW IS DPEENDANT ON VASODILATORY PROSTGLANDINS (LIVER cirrhoses, heart failure, nephrotic syndrome)