Neuropeptide Y (NPY): enhancement of blood pressure increase upon alpha-adrenoceptor activation and direct pressor effects in pithed rats.
The effects of neuropeptide Y (NPY) on blood pressure and heart rate were studied in pithed rats. Systemic infusion of NPY in a dose (230 pmol X kg-1 X min-1) which per se did not affect blood pressure enhanced the pressor response to phenylephrine (50 nmol X kg-1 i.v.) and that to electrical stimulation of the sympathetic outflow. In higher doses, NPY caused a pressor effect per se, which was dose-dependently antagonized by nifedipine but not by adrenoceptor antagonists. In conclusion, NPY enhanced the alpha-adrenoceptor-mediated response and had Ca2+-dependent vasoconstrictor activity in vivo.
Dahlöf
C
C
Dahlöf
P
P
Lundberg
J M
JM
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D003655:Decerebrate State; D004558:Electric Stimulation; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D009478:Neuropeptide Y; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D012710:Serum Albumin, Bovine / Q000494:pharmacology
D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D011942:Receptors, Adrenergic, alpha; D012710:Serum Albumin, Bovine; D009638:Norepinephrine