Role of endothelium and vasoconstrictor prostanoids in norepinephrine-induced vasoconstriction in isolated rat common carotid arteries.
We investigated the role of endothelium and vasoconstrictor prostanoids in the norepinephrine (NE)-induced vasoconstriction of isolated rat common carotid arteries (CCAs). Isolated CCAs were cannulated with stainless steel cannulae by the cannula inserting method. NE was administered intra- or extraluminally by a single microinjection. For denudation of endothelium, the intimal surface was gently rubbed with a cotton pellet. NE produced dose-related vasoconstricting responses in isolated arteries with intact endothelium. These responses were attenuated by pretreatment with denudation, OKY046, a thromboxane A2 synthesis inhibitor or indomethacin. The residual responses after denudation were further blocked by OKY046 or indomethacin. All NE-induced responses were blocked by a single injection of prazosin. There were no significant differences in responses between intra- and extraluminal administration of NE. These results show that most vasoconstriction induced by NE via alpha1-adrenoceptors in CCAs is dependent on vasoconstrictor prostanoids distributed both in endothelium and vascular smooth muscle.
The Third Department of Internal Medicine, Gifu University School of Medicine, Japan.
N
N
Furuhashi
S
S
Miyazaki
M
M
Kamura
S
S
Emura
K
K
Yasuda
D000818:Animals; D017536:Carotid Artery, Common / Q000187:drug effects* / Q000502:physiology*; D004730:Endothelium, Vascular / Q000502:physiology*; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008689:Methacrylates / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology*; D010477:Perfusion; D044262:Prostaglandin H2; D011453:Prostaglandins / Q000502:physiology*; D011463:Prostaglandins H / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology; D013928:Thromboxane A2 / Q000502:physiology; D014661:Vasoconstriction / Q000187:drug effects* / Q000502:physiology*
D008689:Methacrylates; D011453:Prostaglandins; D011463:Prostaglandins H; D018340:Receptors, Adrenergic, alpha-1; D044262:Prostaglandin H2; D013928:Thromboxane A2; C034364:ozagrel; D009638:Norepinephrine; D007213:Indomethacin