Artículos de revistas
alpha 1 and alpha 2-adrenoceptors in the medial amygdaloid nucleus modulate differently the cardiovascular responses to restraint stress in rats
Fecha
2012Registro en:
PHARMACOLOGICAL RESEARCH, LONDON, v. 66, n. 2, supl., Part 3, pp. 154-162, AUG, 2012
1043-6618
10.1016/j.phrs.2012.04.004
Autor
Trindade Fortaleza, Eduardo Albino
Scopinho, America Augusto
de Aguiar Correa, Fernando Morgan
Institución
Resumen
Medial amygdaloid nucleus (MeA) neurotransmission has an inhibitory influence on cardiovascular responses in rats submitted to restraint, which are characterized by both elevated blood pressure (BP) and intense heart rate (HR) increase. In the present study, we investigated the involvement of MeA adrenoceptors in the modulation of cardiovascular responses that are observed during an acute restraint. Male Wistar rats received bilateral microinjections of the selective alpha 1-adrenoceptor antagonist WB4101 (10, 15, and 20 nmol/100 nL) or the selective alpha 2-adrenoceptor antagonist RX821002 (10, 15, and 20 nmol/nL) into the MeA, before the exposure to acute restraint. The injection of WB4101 reduced the restraint-evoked tachycardia. In contrast, the injection of RX821002 increased the tachycardia. Both drugs had no influence on BP increases observed during the acute restraint. Our findings indicate that alpha 1 and alpha 2-adrenoceptors in the MeA play different roles in the modulation of the HR increase evoked by restraint stress in rats. Results suggest that alpha 1-adrenoceptors and alpha 2-adrenoceptors mediate the MeA-related facilitatory and inhibitory influences on restraint-related HR responses, respectively. (C) 2012 Elsevier Ltd. All rights reserved.