Vasoactivity of endothelin in nasal blood vessels.
Endothelin (ET) is a newly described peptide that was isolated from the supernatant of cultured porcine aortic endothelial cells. Among the three isoforms of ET, the originally discovered ET-1 is the only one that exists in vascular endothelium. It is reported to be an extremely potent vasoconstrictor in a variety of blood vessels. Using in vitro bioassay technique, the vasoactivity of ET-1 in both canine and human nasal mucosa was investigated. ET produces a contraction which is slow in onset and sustained in the blood vessels both of the canine and the human nasal mucosa. The threshold of ET-1 in causing contraction was 10(-9) M (dog) and 10(-8) M (human). This response was turned out to be extracellular Ca(2+)-dependent, because either Ca(2+)-free medium or application of nifedipine almost abolished it. A subthreshold concentration of ET-1 enhances exogenously applied noradrenaline (NA)-induced contractions, but not endogenous NA-induced contractions caused by transmural electrical stimulation. As endothelium derived substances, such as ET-1 showed strong vasoactivity, endothelium may play an important role in maintaining vascular tension of the nasal blood vessels along with neural control.
Ichimura
K
K
Dept. of O.R.L., Faculty of Medicine, University of Tokyo, Japan.
Okita
W
W
Tanaka
T
T
D000818:Animals; D002118:Calcium / Q000502:physiology; D004285:Dogs; D016232:Endothelins / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009297:Nasal Mucosa / Q000098:blood supply*; D014661:Vasoconstriction / Q000502:physiology; D014662:Vasoconstrictor Agents
D016232:Endothelins; D014662:Vasoconstrictor Agents; D002118:Calcium