Vascular smooth muscle relaxation by endothelium-dependent beta 1-adrenergic action.
1. Norepinephrine (NE) (10(-5) M) in rabbit aorta relaxed ring segments with endothelium precontracted with 10(-6) M NE, but not segments without endothelium. 2. The relaxation was inhibited with metoprolol and methylene blue, but not inhibited with yohimbine and indomethacin. 3. NE (10(-5) M) significantly elevated tissue c-GMP levels in segments with endothelium. 4. These studies suggest that the vascular relaxation by high doses of NE is mediated by the release of endothelium-derived relaxing factor (EDRF) induced by the stimulation of beta 1-adrenoceptor.
Aikawa
J
J
Third Department of Internal Medicine, Toho University School of Medicine, Tokyo, Japan.
Akatsuka
N
N
D000818:Animals; D001011:Aorta; D006152:Cyclic GMP / Q000378:metabolism; D004730:Endothelium, Vascular / Q000502:physiology*; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008751:Methylene Blue / Q000494:pharmacology; D008790:Metoprolol / Q000494:pharmacology; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D015016:Yohimbine / Q000494:pharmacology
D011943:Receptors, Adrenergic, beta; D015016:Yohimbine; D009569:Nitric Oxide; D008790:Metoprolol; D006152:Cyclic GMP; D008751:Methylene Blue; D009638:Norepinephrine; D007213:Indomethacin