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NK 1 receptors in the paraventricular nucleus are not involved in the regulation of the cardiovascular responses induced by chemoreflex stimulation
Author(s) -
Silva Nathalia Teodoro,
Haibara Andrea Siqueira
Publication year - 2013
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.27.1_supplement.lb849
Subject(s) - microinjection , stimulation , medicine , endocrinology , receptor , chemistry , reflex , glutamate receptor
Studies have shown that paraventricular nucleus (PVN) is involved in the control of the simpathoexcitatory component of the chemoreflex. However the receptors involved in the neurotransmission of this reflex still are not known. Studies have shown that glutamate, GABA or nitric oxide receptors in the PVN are not involved in the chemoreflex responses. This study evaluated the effect of blockade of substance P receptors (NK 1 receptors) in the PVN on the cardiovascular responses of the chemoreflex induced by intravenous injection of potassium cyanide (KCN) in conscious rats. Bilateral microinjection of CP 99,994, NK 1 receptor antagonist, into the PVN produced no significant changes on the pressor response (+39 ± 3 vs +34 ± 4 mmHg) and bradycardia (−225 ± 15 vs −207 ± 21 bpm) of the chemoreflex. Furthermore, the bilateral microinjection of CP 99,994 also produced no changes on baseline cardiovascular parameters (114 ± 4 vs 117 ± 4 mmHg; 390 ± 11 vs 388 ± 14 bpm). These results indicate that NK 1 receptors in the PVN are not involved in the regulation of the cardiovascular parameters during baseline or chemoreflex stimulation. Support: INCT‐CNPq/ CAPES/ FAPEMIG.