Influence of cardiopulmonary reflex on the sympathetic activity during myocardial infarction.
Auton Neurosci
; 133(2): 128-35, 2007 May 30.
Article
em En
| MEDLINE
| ID: mdl-17188942
The time-course of changes in renal sympathetic nerve activity (RSNA), arterial and cardiopulmonary baroreflexes sensitivities was evaluated in conscious rats eight hours (8 h) and ten days (10 day) after myocardial infarction (MI), induced by coronary artery ligation. RSNA was recorded by a platinum electrode implanted in left renal nerve. Arterial and cardiopulmonary baroreflexes sensitivities were evaluated by changes in blood pressure and serotonin administration, respectively. Both 8 h and 10 day groups presented hypotension (103+/-4 vs. 102+/-2 vs. 115+/-4 mm Hg), but only 8 h showed tachycardia (422+/-22 vs. 378+/-11 vs. 384+/-9 bpm) when compared to Control rats. RSNA was depressed 8 h after MI and increased in 10 day group (12+/-2 vs. 39+/-8 vs. 22+/-2 mV/cycle). Although arterial baroreflex control of heart rate was similar in all groups, the arterial baroreflex control of RSNA in 8 h group was impaired during reductions (-0.35+/-0.10 vs. -1.66+/-0.23 vs. -0.09+/-0.14 mV/cycle/mm Hg) or increases (-0.77+/-0.17 vs. -1.63+/-0.58 vs. -1.66+/-0.17 mV/cycle/mm Hg) in blood pressure when compared to Control animals. Moreover, cardiopulmonary baroreflex bradycardic response was increased in 8 h rats and normalized in 10 day group. The results suggest that the increased cardiopulmonary baroreflex sensitivity in 8 h may contribute to the reduction in the tonic level of RSNA as well as in the impairment of the baroreflex control of RSNA in the presence of hypotension.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Artéria Renal
/
Fibras Simpáticas Pós-Ganglionares
/
Barorreflexo
/
Infarto do Miocárdio
Limite:
Animals
Idioma:
En
Revista:
Auton Neurosci
Assunto da revista:
NEUROLOGIA
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda