Prostaglandins in enhanced pressor response in renal prehypertensive rabbits

Abstract

The role of prostaglandins (PGs) in the pressor response to norepinephrine (NE) was examined in one-kidney, one clip rabbits with renal artery stenosis for 3-day's duration (3-day clipped rabbits) and in sham operated rabbits with one-kidney without renal artery stenosis. An exaggerated pressor response to NE, 800 ng/kg/min, was observed in the 3-day clipped rabbits, and it was abolished by angiotensin II antagonist, [Sar 1, Ile 8] angiotensin II (AIIA). Treatment with indomethacin, 10 mg/kg, induced hyperresponsiveness to NE in the sham operated rabbits and also produced a further increase in the response in the 3-day clipped rabbits: the enhanced responses with similar levels were not attenuated by AIIA in both groups. A subdepressor dose of PGE 2, 800 ng/kg/min, abolished the hyperresponsiveness in the 3-day clipped rabbits, while subdepressor or depressor dose of PGI 2, 10 or 20 ng/kg/min did not, but the concurrent infusion of AIIA with PGI 2 attenuated it. These results indicate that PGs, in particular PGE 2 might be involved in the enhanced pressor response to NE in the 3-day clipped rabbits in addition to the altered renin-angiotensin system.