Angiotensin II-induced vasodilatation in cerebral arteries is mediated by endothelium-derived hyperpolarising factor.
The angiotensin II-induced vasodilatation was evaluated in rat middle cerebral artery, especially regarding endothelium-derived hyperpolarising factor (EDHF), by use of a pressurised arteriograph. The angiotensin II dilatation was partly antagonised by inhibitors of nitric oxide synthase and cyclo-oxygenase. The remaining dilatation was inhibited by the potassium channel blockers, charybdotoxin and apamin, providing direct evidence that angiotensin II induces EDHF-mediated dilatation in cerebral arteries. The angiotensin II dilatation was blocked by the angiotensin AT1 and AT2 receptor blockers candesartan and PD 123319. Both angiotensin AT1 and AT2 receptors were detected on the endothelium by immunohistochemistry.
Wackenfors
Angelica
A
Division of Experimental Vascular Research, Department of Clinical Science, Lund University Hospital, Lund, Sweden. angelica.wackenfors@med.lu.se
Vikman
Petter
P
Nilsson
Elisabeth
E
Edvinsson
Lars
L
Malmsjö
Malin
M
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001030:Apamin / Q000494:pharmacology; D001562:Benzimidazoles / Q000494:pharmacology; D001685:Biological Factors / Q000502:physiology*; D001713:Biphenyl Compounds; D002536:Cerebral Arteries / Q000187:drug effects* / Q000502:physiology; D018999:Charybdotoxin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D009498:Neurotoxins / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D019335:Nitroarginine / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000494:pharmacology; D013777:Tetrazoles / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D047228:Angiotensin II Type 1 Receptor Blockers; D000894:Anti-Inflammatory Agents, Non-Steroidal; D001562:Benzimidazoles; D001685:Biological Factors; D001713:Biphenyl Compounds; D004791:Enzyme Inhibitors; D007093:Imidazoles; D009498:Neurotoxins; D011725:Pyridines; D013777:Tetrazoles; D014662:Vasoconstrictor Agents; C067410:endothelium-dependent hyperpolarization factor; D000804:Angiotensin II; D018999:Charybdotoxin; C073402:PD 123319; D019335:Nitroarginine; D001030:Apamin; D012701:Serotonin; D000255:Adenosine Triphosphate; D019001:Nitric Oxide Synthase; C081643:candesartan; D007213:Indomethacin