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Reflexos cardiopulmonares vagales después de la desdiferenciación ventricular izquierda
1Department of Medicine, Medical College of Virginia/Virginia Commonwealth University, Richmond.
Circulation
|October 1, 1994
Resumen
Las fibras nerviosas aferentes vagales del ventrículo izquierdo (LV) se interrumpieron para estudiar su papel en la regulación de la actividad del nervio simpático renal (RSNA). La pérdida de entrada de LV tuvo efectos modestos, lo que sugiere que otros receptores cardiopulmonares compensan.
Área de la Ciencia:
- Fisiología cardiovascular fisiología cardiovascular.
- Regulación del sistema nervioso autónomo.
- Fisiología renal Fisiología renal.
Sus antecedentes:
- Las fibras nerviosas aferentes vagales, principalmente de los ventrículos, son interrumpidas por eventos cardíacos como el trasplante y el infarto de miocardio.
- Se observan anormalidades en los reflejos cardiopulmonares mediados por fibras aferentes vagales después del trasplante cardíaco y el infarto de miocardio.
- La relación entre estas anomalías reflejas y la desdiferenciación ventricular sigue sin estar clara.
Objetivo del estudio:
- Para investigar el impacto de la desdiferenciación ventricular izquierda (LV) en el control del reflejo cardiopulmonar vagal de la actividad del nervio simpático renal (RSNA).
- Para evaluar el papel de la entrada de los aferentes vagales de LV en la modulación de las respuestas de RSNA a los cambios hemodinámicos.
Principales métodos:
- Se investigó el control del reflejo cardiopulmonar vagal de RSNA en perros utilizando anestesia con cloralosa y denervación sinoaórtica.
- Medido la presión auricular izquierda (LAP) y las respuestas RSNA a la hemorragia y la expansión del volumen antes y después de la desdiferenciación de LV con fenol.
- Se utilizó la sonomicrometría para evaluar la longitud del segmento miocárdico LV y la nicotina intracoronaria para confirmar la diferenciación.
Principales resultados:
- La desdiferenciación de LV atenuó ligeramente la sensibilidad del reflejo cardiopulmonar vagal durante la expansión del volumen (P < .05).
- No se observó ninguna alteración significativa en la sensibilidad refleja durante la hemorragia después de la desdiferenciación de LV.
- La nicotina intracoronaria no pudo inhibir el RSNA después de la desferenciación, lo que confirma una desferenciación ventricular efectiva.
Conclusiones:
- La interrupción de la entrada de los aferentes vaga de la LV ejerce sólo efectos modestos en el control de la RSNA por el reflejo cardiopulmonar vagal.
- El reflejo cardiopulmonar vagal exhibe una redundancia significativa, con los receptores de la cámara cardíaca pulmonar y otros que compensan la pérdida de entrada aferente de LV.
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