AT(2) and MAS (but not AT(1)) angiotensinergic receptors in the medial amygdaloid nucleus modulate the baroreflex activity in rats

Autor(es)

Costa-Ferreira, Willian ^{[1, 2]} ; Gomes-de-Souza, Lucas ^{[1, 2]} ; Crestani, Carlos C. ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Joint UFSCar UNESP Grad Program Physiol Sci, Sao Carlos, SP - Brazil

^[2] Sao Paulo State Univ UNESP, Sch Pharmaceut Sci, Pharmacol Lab, Rodovia Araraquara Jau Km 01 Campus Univ, BR-14800903 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY; v. 471, n. 9, p. 1173-1182, SEP 2019.
• Citações Web of Science: 0

Resumo

The medial amygdaloid nucleus (MeA) is a limbic structure that has been demonstrated to be part of the central circuitry regulating baroreflex function. However, the local neurochemical mechanisms involved in baroreflex control by this forebrain structure is poorly understood. Thus, in the present study, we investigated the specific role of AT(1), AT(2), and MAS angiotensinergic receptors within the MeA in baroreflex responses in unanesthetized rats. For this, the baroreflex function was assessed using both the pharmacological approach via intravenous infusion of vasoactive agents and the sequence analysis technique. Using the pharmacological approach, we observed that bilateral microinjection of the selective AT(2) receptor antagonist PD123319 into the MeA increased the tachycardia evoked by blood pressure decrease, but without affecting the reflex bradycardia caused by blood pressure increase. Besides, bilateral microinjection of the selective MAS receptor antagonist A-779 decreased both tachycardic and bradycardic responses of the baroreflex. The sequence analysis technique indicated that PD123319 into the MeA increased baroreflex effectiveness index while A-779 had an opposite effect. Treatment of the MeA with the selective AT(1) receptor antagonist losartan did not affect baroreflex function assessed by either the pharmacological approach or sequence analysis technique. Overall, these findings provide evidence that MAS receptor within the MeA plays a facilitatory role in baroreflex function, whereas local AT(2) receptor inhibits cardiac baroreflex responses. Results also indicate that AT(1) receptor within the MeA is not involved in the control of baroreflex function. (AU)

• Processo FAPESP: 15/05922-9 - Estudo da participação da neurotransmissão CRFérgica do núcleo leito da estria terminal nas alterações cardiovasculares induzidas pelo estresse: interação com a via de sinalização receptor NMDA / óxido nítrico/guanilato ciclase / proteína quinase g?
• Beneficiário: Carlos Cesar Crestani
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 16/05218-2 - Envolvimento das sinalizações angiotensina II/receptor AT1 e angiotensina 1-7/ receptor Mas no núcleo medial da amígdala nas respostas cardiovasculares e ansiogênica ao estresse em ratos
• Beneficiário: Willian Costa Ferreira
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 17/19249-0 - Envolvimento de neurotransmissões angiotensinérgicas do núcleo medial da amígdala no controle das respostas cardiovasculares e ansiogênica ao estresse em ratos.
• Beneficiário: Carlos Cesar Crestani
• Modalidade de apoio: Auxílio à Pesquisa - Regular