Neuropeptide Y and Y1-receptor agonists increase blood flow through arteriovenous anastomoses in rat tail.
The purpose of this study was to characterize neuropeptide Y (NPY)-induced vasodilation in the rat tail. Sterile surgical technique was used (with pentobarbital sodium anesthesia) to equip rats with a jugular catheter and a blind-ended thermocouple reentrant tube next to the carotid artery. Tail skin and core temperature were measured with thermocouples during experiments. Tail skin blood flow was monitored with a laser Doppler flowmeter, and tail total blood flow and volume were measured with plethysmography. After baseline data were collected, saline, NPY (16, 32, 64, and 128 microg/kg), [Leu31 Pro34]NPY (63.25 microg/kg), or NPY[13-36] (44.7 microg/kg) was administered intravenously. Tail total blood flow, volume, and tail skin temperature increased, whereas tail skin blood flow and core temperature decreased in response to both NPY- and the Y1-receptor agonist [Leu31 Pro34]NPY but not in response to saline or NPY[13-36]. Studies conducted with the use of color microspheres demonstrated that arteriovenous anastomoses are involved in this NPY-induced vasodilation.
Heath
M E
ME
Thermal Stress/Adaptation, Naval Medical Research Institute, Bethesda, Maryland 20889-5607, USA. MEHeath@compuserve.com
D000818:Animals; D001163:Arteriovenous Anastomosis / Q000187:drug effects*; D001831:Body Temperature / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D008297:Male; D008863:Microspheres; D051381:Rats; D017476:Receptors, Neuropeptide Y / Q000819:agonists*; D012039:Regional Blood Flow / Q000187:drug effects; D013623:Tail / Q000098:blood supply*; D014664:Vasodilation / Q000187:drug effects
D017476:Receptors, Neuropeptide Y; C097212:neuropeptide Y-Y1 receptor; C095889:neuropeptide Y2 receptor