Vasopressin dilates the rat carotid artery by stimulating V1 receptors.
The acute effects of various vasopressor agents on the diameter of the common carotid artery were studied in halothane-anesthetized normotensive rats. The animals were infused intravenously for 60 min with equipressor doses of angiotensin II (10 ng/min), the alpha1-stimulant methoxamine (5 microg/min), lysine vasopressin (5 mU/min), or vehicle. The arterial diameter was measured by using a high-resolution ultrasonic echo-tracking device. The three vasoconstrictors increased the carotid artery diameter, but this effect was significantly more pronounced with lysine vasopressin. Even a nonpressor dose of lysine vasopressin (1 mU/min) caused a significant increase in the arterial diameter. The lysine vasopressin-induced vasodilatation could be prevented by the administration of d(CH2)5Tyr(Me)AVP (10 microg, i.v.), a selective V1-vasopressinergic receptor antagonist. These data therefore suggest that a short-term increase in blood pressure induces in rats a distention of the carotid artery. The increase in arterial diameter seems to involve an active mechanism with lysine vasopressin caused by the stimulation of V1-vasopressinergic receptors.
Division of Hypertension, University Hospital, Lausanne, Switzerland.
B
B
Rutschmann
D
D
Evequoz
J F
JF
Aubert
H R
HR
Brunner
B
B
Waeber
D000804:Angiotensin II / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D065092:Antidiuretic Hormone Receptor Antagonists; D001127:Arginine Vasopressin / Q000031:analogs & derivatives* / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002339:Carotid Arteries / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006727:Hormone Antagonists / Q000494:pharmacology*; D007262:Infusions, Intravenous; D008236:Lypressin / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008297:Male; D008729:Methoxamine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017483:Receptors, Vasopressin / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D014664:Vasodilation / Q000187:drug effects*
D065092:Antidiuretic Hormone Receptor Antagonists; D006727:Hormone Antagonists; D017483:Receptors, Vasopressin; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D001127:Arginine Vasopressin; D008236:Lypressin; C025043:vasopressin, 1-(1-mercaptocyclohexaneacetic acid)-2-(O- methyl-L-tyrosine)-8-L-arginine-; D008729:Methoxamine