Inhibitory action of prostaglandin E on angiotensin II-induced enhancement of vasoconstrictor response to sympathetic nerve stimulation.
The inhibitory action of prostaglandin E1 (PGE1) on the vasoconstrictor response to an electrical stimulation of perivascular sympathetic nerve (VSNS) was examined using the perfused central artery of an isolated rabbit ear. This response to VSNS was depressed with PGE1 (2.0 to 5.0 ng/ml in the perfusate) and was augmented with a PG synthetase inhibitor, indomethacin (1.0 microgram/ml). Angiotensin II (1.0 ng/ml) enhanced the response to VSNS, whereas treatment with PGE1 prevented the enhancing effect of angiotensin II completely. In addition, angiotensin II enhanced the response to a bolus injection of noradrenaline in an almost similar manner to that to VSNS. However, PGE1 (2.0 to 5.0 ng/ml) did not inhibit the enhancing effect of angiotensin II on the noradrenaline response. From these results, it is suggested that there may be remarkable antagonism between PGE and the sympathetic nervous system and/or the renin-angiotensin system in the central artery of the isolated rabbit ear, and that PGE1 probably and more potentially acts at presynaptic sites in perivascular sympathetic nerve endings than at postsynaptic ones.
D000527:Alprostadil; D000804:Angiotensin II / Q000037:antagonists & inhibitors*; D000818:Animals; D004558:Electric Stimulation; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D010646:Phentolamine / Q000494:pharmacology; D011458:Prostaglandins E / Q000494:pharmacology*; D011817:Rabbits; D013564:Sympathetic Nervous System / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects*
D011458:Prostaglandins E; D000804:Angiotensin II; D013779:Tetrodotoxin; D000527:Alprostadil; D007213:Indomethacin; D010646:Phentolamine