| Journal: | Brazilian journal of medical and biological research |
| Database: | PERIÓDICA |
| System number: | 000349536 |
| ISSN: | 0100-879X |
| Authors: | Biancardi, V.C1 Bergamaschi, C.T1 Lopes, O.U1 Campos, R.R1 |
| Institutions: | 1Universidade Federal de Sao Paulo, Escola Paulista de Medicina, Sao Paulo. Brasil |
| Year: | 2007 |
| Season: | Mar |
| Volumen: | 40 |
| Number: | 3 |
| Pages: | 401-408 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental, aplicado |
| English abstract | We evaluated the hemodynamic pattern and the contribution of the sympathetic nervous system in conscious and anesthetized (1.4 g/kg urethane, iv) Wistar rats with L-NAME-induced hypertension (20 mg/kg daily). The basal hemodynamic profile was similar for hypertensive animals, conscious (N = 12) or anesthetized (N = 12) treated with L-NAME for 2 or 7 days: increase of total peripheral resistance associated with a decrease of cardiac output (CO) compared to normotensive animals, conscious (N = 14) or anesthetized (N = 14). Sympathetic blockade with hexamethonium essentially caused a decrease in total peripheral resistance in hypertensive animals (conscious, 2 days: from (means ± SEM) 2.47 ± 0.08 to 2.14 ± 0.07; conscious, 7 days: from 2.85 ± 0.13 to 2.07 ± 0.33; anesthetized, 2 days: from 3.00 ± 0.09 to 1.83 ± 0.25 and anesthetized, 7 days: from 3.56 ± 0.11 to 1.53 ± 0.10 mmHg mL-1 min-1) with no change in CO in either group. However, in the normotensive group a fall in CO (conscious: from 125 ± 4.5 to 96 ± 4; anesthetized: from 118 ± 1.5 to 104 ± 5.5 mL/min) was observed. The responses after hexamethonium were more prominent in the hypertensive anesthetized group. However, no difference was observed between conscious and anesthetized normotensive rats in response to sympathetic blockade. The present study shows that the vasoconstriction in response to L-NAME was mediated by the sympathetic drive. The sympathetic tone plays an important role in the initiation and maintenance of hypertension |
| Disciplines: | Biología |
| Keyword: | Fisiología animal, Hipertensión, Sistema nervioso simpático, Bloqueo nervioso, Oxido nítrico sintetasa, Resistencia periférica, Ratas |
| Keyword: | Biology, Animal physiology, Hypertension, Sympathetic nervous system, Nervous blockade, Nitric oxide synthase, Peripheral resistance, Rats |
| Full text: | Texto completo (Ver HTML) |
