Excitatory effects of nitric oxide within the rostral ventrolateral medulla of freely moving rats

Excitatory effects of nitric oxide within the rostral ventrolateral medulla of freely moving rats

Autor Pinge, Marli Cardoso Martins Autor UNIFESP Google Scholar
Passy, Izabel Baraldi Autor UNIFESP Google Scholar
Lopes, Oswaldo Ubriaco Autor UNIFESP Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Resumo The aim of the present study was to examine the participation of NO in the rostral ventrolateral medulla (RVLM) of freely moving rats. We utilized NO donors and L-arginine, which were microinjected into the RVLM. Unilateral microinjection (100 nL) of 2.5 nmol sodium nitroprusside produced a biphasic response consisting of an initial, rapid increase in arterial pressure (AP) from 125+/-5 to 161+/-8 mm Hg (P<.01) and a second, long-lasting response with a progressive increase in AP (maximum Delta peak, 34+/-9 mm Hg; P<.01). Another NO donor, S-nitroso-N-acetylpenicillamine (SNAP; 2.5 nmol), also produced immediate hypertension from 118+/-5 mm Hg to 168+/-7 mm Hg (P<.01) but without the second, long-lasting response. L-Arginine (5, 24, and 140 nmol) produced a gradual increase in AP. L-Glutamate (5 nmol) microinjected into the RVLM produced an increase in AP from 122+/-9 mm Hg to 171+/-8 mm Hg (P<.01) and bradycardia from 342+/-10 to 315+/-8 beats/min. This AP response was significantly attenuated, from 115+/-7 to 128+/-9 mm Hg (P<.05), after microinjection of methylene blue (3 nmol) without alterations In heart rate. These results indicate that NO may have an excitatory effect on the RVLM of freely moving rats, probably in association with glutamatergic synapses via cGMP mechanisms.
Assunto amino acids
blood pressure, arterial
brain
nitric oxide
rostral ventrolateral medulla
Idioma Inglês
Data 1997-09-01
Publicado em Hypertension. Dallas: Amer Heart Assoc, v. 30, n. 3, p. 704-707, 1997.
ISSN 0194-911X (Sherpa/Romeo, fator de impacto)
Editor Amer Heart Assoc
Extensão 704-707
Fonte https://doi.org/10.1161/01.HYP.30.3.704
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:A1997XY88000033
URI http://repositorio.unifesp.br/11600/43846

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