Premium
Cardiovascular effects of noradrenaline injected into the Medial Nucleus of Amígdala (MeA) of unanesthetized rats.
Author(s) -
Fortaleza Eduardo Trindade,
Scopinho América Augusto,
Correa Fernando Morgan Aguiar
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.1019.11
Subject(s) - locus coeruleus , medicine , endocrinology , neurotransmitter , norepinephrine , stimulation , central nervous system , blood pressure , autonomic nervous system , heart rate , baroreflex , receptor , femoral artery , anesthesia , dopamine
The MeA, is involved with physiological and behavioral processes modulation, as well as regulation of the autonomic nervous system. Some evidences indicating that electrical rats MeA stimulation is able to evoke cardiovascular response. The noradrenaline (NA) is a neurotransmitter involved in the control of cardiovascular responses into the several structures in the central nervous system. The MeA received noradrenergic innervations of the A6 neurons and locus coeruleus (LC). Moreover, binding studies demonstrate noradrenergic receptors in this area. Objective The aim of the present work is characterize the cardiovascular responses evoked by local administration of NA in the MeA. Methods and Results Male Wistar rats were used. Cannulaes was implanted in the MeA using a stereotaxic apparatus. A catheter was implanted into the femoral artery for blood pressure and heart rate (HR) recording. Injecting different doses of NA (3, 9, 27 or 45 nmol/100 nL) into the MeA of normotensive rats (baseline MAP=100±2 mmHg and HR=369 ± 4bpm, n=25) caused dose‐related pressor responses and HR decrease. Nonlinear regression analysis indicated a significant correlation between doses and cardiovascular responses. Conclusion Our results reinforce the idea that noradrenergic mechanisms into the MeA are involved in cardiovascular control. Financial Supports FAPESP, CNPQ and FAEPA.