Bed nucleus of the stria terminalis α1- and α2-adrenoceptors differentially modulate the cardiovascular responses to exercise in rats.
Neuroscience
; 177: 74-83, 2011 Mar 17.
Article
en En
| MEDLINE
| ID: mdl-21219971
Dynamic exercise evokes sustained blood pressure and heart rate (HR) increases. Although it is well accepted that there is a CNS mediation of cardiovascular adjustments during dynamic exercise, information on the role of specific CNS structures is still limited. The bed nucleus of the stria terminalis (BST) is involved in exercise-evoked cardiovascular responses in rats. However, the specific neurotransmitter involved in BST-related modulation of cardiovascular responses to dynamic exercise is still unclear. In the present study, we investigated the role of local BST adrenoceptors in the cardiovascular responses evoked when rats are submitted to an acute bout of exercise on a rodent treadmill. We observed that bilateral microinjection of the selective α1-adrenoceptor antagonist WB4101 into the BST enhanced the HR increase evoked by dynamic exercise without affecting the mean arterial pressure (MAP) increase. Bilateral microinjection of the selective α2-adrenoceptor antagonist RX821002 reduced exercise-evoked pressor response without changing the tachycardiac response. BST pretreatment with the nonselective ß-adrenoceptor antagonist propranolol did not affect exercise-related cardiovascular responses. BST treatment with either WB4101 or RX821002 did not affect motor performance in the open-field test, which indicates that effects of BST adrenoceptor antagonism in exercise-evoked cardiovascular responses were not due to changes in motor activity. The present findings are the first evidence showing the involvement of CNS adrenoceptors in cardiovascular responses during dynamic exercise. Our results indicate an inhibitory influence of BST α1-adrenoceptor on the exercise-evoked HR response. Data also point to a facilitatory role played by the activation of BST α2-adrenoceptor on the pressor response to dynamic exercise.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Condicionamiento Físico Animal
/
Núcleos Septales
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Tolerancia al Ejercicio
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Receptores Adrenérgicos alfa 2
/
Receptores Adrenérgicos alfa 1
Límite:
Animals
Idioma:
En
Revista:
Neuroscience
Año:
2011
Tipo del documento:
Article
País de afiliación:
Brasil
Pais de publicación:
Estados Unidos