A FALL in ARTERIAL BLOOD-PRESSURE PRODUCED BY INHIBITION of the CAUDALMOST VENTROLATERAL MEDULLA - the CAUDAL PRESSER AREA

A FALL in ARTERIAL BLOOD-PRESSURE PRODUCED BY INHIBITION of the CAUDALMOST VENTROLATERAL MEDULLA - the CAUDAL PRESSER AREA

Autor Possas, O. S. Google Scholar
Campos, R. R. Google Scholar
Cravo, S. L. Google Scholar
Lopes, O. U. Google Scholar
Guertzenstein, P. G. Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Resumo The caudal edge of the ventrolateral medulla was mapped to localize sites where microinjections of L-glutamate (L-glu) produce presser responses in paralyzed and artificially ventilated urethane-anesthetized rats. Presser responses ranging from 15 to 65 mmHg were obtained when L-Glu (0.25 M, 200 nl) was microinjected in the ventral medullary surface within an area localized between the rootlets of the XII and first cervical nerves, lateral to the pyramids and just medial to the spinal roots of the XI cranial nerve. This area has been called the caudal presser area (CPA). Inhibition of the CPA by microinjection of GABA or glycine resulted in marked falls (15-45 mmHg) of arterial blood pressure (AP). Hypotension in response to CPA inhibition was also obtained in unanesthetized decerebrate animals. Cardiovascular responses to CPA stimulation or inhibition depend on the activity of neurons in the rostral ventrolateral medulla (RVLM). During hypotension provoked by RVLM inhibition, presser responses to CPA stimulation were abolished. Conversely, presser responses to RVLM stimulation were maintained during hypotension produced by inhibition of CPA, Presser response to bilateral carotid occlusion were not reduced by CPA inhibition. We conclude that cells in the caudal most ventrolateral medulla exert a tonic presser activity that contributes to maintenance of basal levels of the vasomotor tone and arterial blood pressure, its inhibition, however, does not prevent the presser response to carotid occlusion.
Palavra-chave VENTROLATERAL MEDULLA
VASOMOTOR TONE
CAROTID OCCLUSION
GABA
GLYCINE
Idioma Inglês
Data de publicação 1994-11-01
Publicado em Journal of the Autonomic Nervous System. Amsterdam: Elsevier B.V., v. 49, n. 3, p. 235-245, 1994.
ISSN 0165-1838 (Sherpa/Romeo, fator de impacto)
Publicador Elsevier B.V.
Extensão 235-245
Fonte http://dx.doi.org/10.1016/0165-1838(94)90170-8
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:A1994PG18000006
Endereço permanente http://repositorio.unifesp.br/handle/11600/25440

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