[Neuropeptide Y, orthosympathetic nervous system, hypertension and alpha-2 adrenergic receptors].
Neuropeptide Y (NPY) is coreleased with noradrenaline (NA) from sympathetic nerve endings. In vitro data suggest that NPY is coreleased during high stimulation frequencies. The present study investigates plasma levels of catecholamines and neuropeptide Y (NPY) during changes in sympathetic nervous activity in conscious dogs. Increase in sympathetic tone: arterial hypertension elicited by sinoaortic denervation induced an increase (X 2) in plasma noradrenaline (NA) but no change in NPY levels. High (0.5 mg/kg i.v.) but not low (0.05 mg/kg i.v.) doses of yohimbine rose plasma NPY concentrations. Decrease in sympathetic tone: clonidine (10 micrograms/kg i.v.) but not beta-blocking agents (propranolol or atenolol: 1 mg/kg i.v.) reduced plasma NPY levels. These results show that NPY is correleased in vivo from sympathetic nerve endings during marked and rapid increases in sympathetic tone. They suggest a lack of relationship between NA and NPY release. Alpha 2-adrenoceptors are involved in the presynaptic control of NPY release from sympathetic tone. Finally, some antihypertensive drugs (clonidine but not beta-blocking agents) are able to decrease plasma NPY levels.
Poncet
M F
MF
Laboratoire de pharmacologie médicale et clinique, INSERM U317, faculté de médecine, Toulouse.
Tavernier
G
G
Damase-Michel
C
C
Tran
M A
MA
Berlan
M
M
Montastruc
J L
JL
Montastruc
P
P
D000818:Animals; D002985:Clinical Protocols; D003000:Clonidine / Q000494:pharmacology; D004285:Dogs; D006973:Hypertension / Q000097:blood* / Q000503:physiopathology; D009478:Neuropeptide Y / Q000097:blood* / Q000502:physiology; D009638:Norepinephrine / Q000097:blood / Q000502:physiology; D011433:Propranolol / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology*; D015016:Yohimbine / Q000008:administration & dosage
D009478:Neuropeptide Y; D011942:Receptors, Adrenergic, alpha; D015016:Yohimbine; D011433:Propranolol; D003000:Clonidine; D009638:Norepinephrine
Neuropeptide Y, système nerveux orthosympathique, hypertension arterielle et récepteurs alpha 2-adrénergiques.