Comparison of the haemodynamic actions of neuropeptide Y, angiotensin II and noradrenaline in anaesthetised cats.
Blood pressure, heart rate, cardiac output, renal flow and femoral flow were recorded in open-chested anaesthetised cats. Dose-response curves were constructed for neuropeptide Y, angiotensin II and noradrenaline after pretreatment with atropine sulphate. Neuropeptide Y, on a molar basis, was 7 and 120 times less potent than noradrenaline and angiotensin, respectively, in producing a 50 mm Hg rise in mean arterial blood pressure. The pressor effect of neuropeptide Y was characterised by dose-dependent increases in total peripheral, renal and femoral resistance with little change in cardiac output. Neuropeptide Y had a similar potency to noradrenaline in causing these resistance changes. However, the pressor response to noradrenaline was associated with a dose-dependent increase in cardiac output. The pressor action of neuropeptide Y was not attenuated by adrenoceptor blockade by phenoxybenzamine (5 mg kg-1) and propranolol (1 mg kg-1).
D000758:Anesthesia; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002415:Cats; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D009478:Neuropeptide Y; D009638:Norepinephrine / Q000494:pharmacology*; D012039:Regional Blood Flow / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D009419:Nerve Tissue Proteins; D009478:Neuropeptide Y; D000804:Angiotensin II; D009638:Norepinephrine