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| Silva,N.F.; Pires,J.G.P.; Campos,R.R.; Futuro Neto,H.A.. |
| The role of the caudal pressor area (CPA) in the maintenance of vasomotor tonus in anesthetized and decerebrate animals has been clearly established. In conscious animals, however, the participation of CPA in the cardiovascular control remains to be fully elucidated. In the present study, unilateral L-glutamate (L-Glu) (10 and/or 20 nmol/70 nl) microinjection into CPA, in conscious male Wistar rats (250-280 g) caused a significant increase in mean arterial blood pressure (MAP; control: 112 ± 1.9 mmHg; after 20 nmol L-Glu: 139 ± 4.5 mmHg, N = 12, P<0.05) and respiratory rate (control: 81 ± 3.5 breaths/min; after 10 nmol L-Glu: 92 ± 3 breaths/min, P<0.05; after 20 nmol L-Glu: 104 ± 5 breaths/min, N = 6, P<0.05). The subsequent anesthesia with... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Caudal pressor area; Ventrolateral medulla; Blood pressure; L-glutamate; Respiration. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001001200013 |
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| Lacerda,J.E.C.; Campos,R.R.; Araujo,G.C.; Andreatta-Van Leyen,S.; Lopes,O.U.; Guertzenstein,P.G.. |
| The rostral ventrolateral medulla (RVLM) contains neurons involved in tonic and reflex control of arterial pressure. We describe the effects of gamma-aminobutyric acid (GABA) and anesthetics injected into the RVLM of conscious and urethane (1.2 g/kg, iv) anesthetized Wistar rats (300-350 g). In conscious rats, bilateral microinjection of GABA (50 nmol/200 nl) induced a small but significant decrease in blood pressure (from 130 ± 3.6 to 110 ± 5.6 mmHg, N = 7). A similar response was observed with sodium pentobarbital microinjection (24 nmol/200 nl). However, in the same animals, the fall in blood pressure induced by GABA (from 121 ± 8.9 to 76 ± 8.8 mmHg, N = 7) or pentobarbital (from 118 ± 4.5 to 57 ± 11.3 mmHg, N = 6) was significantly increased after... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vasomotor tone; Ventrolateral medulla; RVLM; GABA; Conscious rats. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000900019 |
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| Silva,N.F.; Pires,J.G.P.; Dantas,M.A.; Futuro Neto,H.A.. |
| Pressor responses elicited by stimulation of the nucleus raphe obscurus (NRO) depend on the integrity of the rostral ventrolateral medulla (RVLM). Therefore, to test the participation of excitatory amino acid (EAA) receptors in the cardiovascular responses evoked by NRO stimulation (1 ms, 100 Hz, 40-70 µA, for 10 s), the EAA antagonist kynurenic acid (Kyn) was microinjected at different sites in the ventrolateral medullar surface (2.7 nmol/200 nl) of male Wistar rats (270-320 g, N = 39) and NRO stimulation was repeated. The effects of NRO stimulation were: hypertension (deltaMAP = +43 ± 1 mmHg, P<0.01), bradycardia (deltaHR = -30 ± 7 bpm, P<0.01) and apnea. Bilateral microinjection of Kyn into the RVLM, which did not change baseline parameters,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Raphe nuclei; Electrical stimulation; Ventrolateral medulla; Caudal pressor area; Excitatory amino acid receptors; Kynurenic acid; Blood pressure. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2002001000019 |
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