Endothelin causes contraction of canine and bovine arterial smooth muscle in vitro and in vivo.
We have studied the effect of endothelin, an endothelium-derived peptide, on isolated canine and bovine cerebral arteries in vitro and on canine vertebral blood flow (VBF) in vivo. Endothelin produced a dose-dependent contraction of canine and bovine arterial smooth muscle with ED50 values ranging from 4 to 8 nM. The response to endothelin developed slowly and persisted as a sustained contraction. Maximal contraction by endothelin required the presence of extracellular calcium and was independent of the presence of endothelium. The maximal contraction produced by endothelin was approximately 2-3 times greater than that produced by neuropeptide Y or angiotensin II. The injection of endothelin into the vertebral artery decreased vertebral blood flow (VBF) dose-dependently without affecting systemic blood pressure or heart rate. The decrease in VBF produced by endothelin was long-lasting, like that produced by neuropeptide Y, but more potent. The present data, together with our previous study demonstrating that the intracisternal injection of endothelin induces an unusually long-lasting decrease in the basilar artery diameter angiographically, suggests that endothelin may act as a long-lasting vasoconstrictor in cerebral vascular disease.
Department of Neurosurgery, Nagoya University School of Medicine, Japan.
Y
Y
Suzuki
S
S
Satoh
I
I
Ikegaki
T
T
Asano
M
M
Shibuya
K
K
Sugita
K
K
Lederis
O
O
Rorstad
D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002417:Cattle; D002536:Cerebral Arteries / Q000187:drug effects / Q000502:physiology*; D004285:Dogs; D016232:Endothelins; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D009478:Neuropeptide Y / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects; D014661:Vasoconstriction / Q000187:drug effects*; D014711:Vertebral Artery / Q000187:drug effects / Q000502:physiology*
D016232:Endothelins; D009478:Neuropeptide Y; D010455:Peptides; D000804:Angiotensin II