Cardiovascular actions of neuropeptide Y in the hypothalamic paraventricular nucleus of conscious Long Evans and Brattleboro rats.
The central cardiovascular effects of neuropeptide Y (NPY) have been investigated by microinjection of the peptide into the hypothalamic paraventricular nucleus (PVN) of conscious rats. NPY (100 ng) elicited a significant bradycardia in both Long Evans (control) rats (-27 +/- beats/min) and vasopressin-deficient Brattleboro rats (-19 +/- 6 beats/min). There was a slight fall in systolic blood pressure in both strains which was significant only in Long Evans rats. A higher dose of NPY (1000 ng) had no significant effect on blood pressure or heart rate, but produced a marked behavioural response characterized by initiation of foraging behaviour. These results provide further support for a role for NPY in central cardiovascular regulation, but provide no evidence of an indispensable involvement of vasopressin-containing pathways in the observed responses.
Harland
D
D
Department of Physiology and Pharmacology, Medical School, Queen's Medical Centre, Nottingham, U.K.
Bennett
T
T
Gardiner
S M
SM
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002320:Cardiovascular Physiological Phenomena; D002319:Cardiovascular System / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D008845:Microinjections; D009478:Neuropeptide Y / Q000494:pharmacology*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011910:Rats, Brattleboro
D009478:Neuropeptide Y