Cardiovascular effects induced by the stimulation of neuropeptide FF receptors in the dorsal vagal complex: an autoradiographic and pharmacological study in the rat

• Published in: Brain research Vol. 711; no. 1; pp. 193 - 202
• Main Authors: Laguzzi, R., Nosjean, A., Mazarguil, H., Allard, M.
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 04-03-1996; Amsterdam Elsevier; New York, NY
• Subjects: Animals; Autoradiography; Baroreceptor reflex; Biological and medical sciences; Blood Pressure; Blood Pressure - drug effects; Cardiorespiratory control. Arterial mecano- and chemoreceptor; Cardiovascular parameter; Cognitive Sciences; Dose-Response Relationship, Drug; Fundamental and applied biological sciences. Psychology; Heart Rate; Heart Rate - drug effects; Life Sciences; Male; Neurobiology; Neurons and Cognition; Neuropeptide FF; Neuropeptides; Neuropeptides - pharmacology; Nucleus tractus solitarius; Oligopeptides; Oligopeptides - pharmacology; Prazosin; Prazosin - pharmacology; Psychology and behavior; Rats; Rats, Sprague-Dawley; Receptor; Vagus Nerve; Vagus Nerve - drug effects; Vertebrates: respiratory system; Nucleus tractus solitarius; Baroreceptor reflex; Neuropeptide FF; Receptor; Cardiovascular parameter; Cardiovascular control; Agonist; Rat; Rodentia; Central nervous system; Dose activity relation; Solitary nucleus; Heart rate; Vertebrata; Mammalia; Peptidergic receptor; Blood pressure; Hemodynamics; Baroreceptor; Brain (vertebrata)
• ISSN: 0006-8993; 1872-6240; 0006-8993
• DOI: 10.1016/0006-8993(95)01382-2

Previous studies have suggested that central administration of neuropeptide FF-related peptides may modulate cardiovascular parameters in the rat. In the present study, we investigated the role of dorsal vagal complex neuropeptide FF receptors in the central regulation of cardiovascular parameters. The fate of neuropeptide FF receptors in normal and nodose ganglionectomized rats was investigated using an autoradiographic approach with
125I-]DTyr
1, (NMe)Phe
3]NPFF as ligand for these receptors. We showed that neuropeptide FF binding sites are preferentially located postsynaptically with respect to the vagal afferent fibers in the nucleus tractus solitarius. Thus, ganglionectomy reduced by only 30% and 17% the density of peptide binding sites in the rostral and caudal regions of this nucleus, respectively. Bilateral microinjection of neuropeptide FF (1 nmol) into the commissural nucleus tractus solitarius produced an increase in blood pressure (+13.8 ± 0.8 mmHg,
n = 6), bradycardia (−29.0 ± 3.2 bpm) and a significant inhibition (−47.6 ± 3.1%) of the cardiac component of the baroreceptor reflex. Further studies with doses below 1 nmol indicate that NTS microinjections of the neuropeptide produced a dose-dependent decrease in heart rate. Similar cardiovascular effects were observed after bilateral NTS microinjections of one analog neuropeptide FF receptor agonist, [DTyr
1, (NMe)Phe
3]NPFF (1 nmol). Pretreatment with prazosin (100 μg/kg), an
α
1-adrenoreceptor antagonist, inhibited the neuropeptide FF-evoked blood pressure effect. In addition, the neuropeptide FF-induced heart rate decrease was abolished by pretreatment with atropine (30 μg/kg, a muscarinic receptor antagonist. Taken together, these anatomical and pharmacological data suggest that neuropeptide FF receptors within the nucleus tractus solitarius, preferentially located on the postsynaptic component, are involved in the central reflex regulation of cardiovascular parameters.