NOP receptors in the prelimbic cortex have an inhibitory influence on cardiovascular responses induced by restraint stress

Autor(es)

Fassini, Aline ^[1] ; Scopinho, America A. ^[1] ; Resstel, Leonardo B. M. ^[1] ; Correa, Fernando M. A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Pharmacol, Sch Med Ribeirao Preto, Ave Bandeirantes 3900, BR-14049900 Ribeirao Preto, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Neuropeptides; v. 57, p. 35-44, JUN 2016.
• Citações Web of Science: 2

Resumo

Nociceptin/orphanin FQ (N/OFQ) and its receptor (NOP) have structural homology with classic opioids, but constitute a distinct neurotransmitter system because they lack affinity for the opioid peptides and receptors. This neurotransmission is implicated in several physiologic processes, but the role played by NOP receptors during stress situations remains unclear. The acute restraint stress (RS) is a model of unavoidable stress, characterized by sustained increases in mean arterial pressure (MAP), heart rate (HR) and a drop in tail temperature. On another side, the prelimbic (PL) and infralimbic (IL) cortices, subdivisions of the medial prefrontal cortex (MPFC), are implicated in the modulation of functional responses caused by RS. Considering that, the objective of the present study was to investigate the involvement of PL and IL NOP receptors in the control of autonomic responses induced by RS. Bilateral microinjection of nociceptin (NOP agonist) into the PL reduced the cardiovascular responses evoked by RS. Bilateral microinjection of UPF-101 (NOP antagonist) into the PL potentiated the pressor and tachycardiac responses evoked by RS, in a dose-dependent manner. Local pretreatment with UPF-101 blocked the RS-evoked changes following nociceptin administration into the PL None of these treatments affected the drop in tail temperature induced by RS. Otherwise, the administration of nociceptin or UPF-101 into the IL had no effect on RS-evoked autonomic changes. To investigate the peripheral mechanism involved in the increase in the RS-evoked cardiovascular responses induced by the blockade of PL NOP receptors, rats were intravenous pretreated with either homatropine or atenolol. The intravenous treatment with homatropine blunted the increase in the RS-evoked pressor and tachycardiac response induced by the PL treatment with UPF101, while the intravenous treatment with atenolol did not affect the RS-evoked pressor and tachycardiac response induced by the PL treatment with UPF-101. In conclusion, our study shows an influence of the PL N/ OFQneurotransmission, but not the IL NOP receptors, in the control of cardiovascular responses observed during acute stress, by increasing cardiac parasympathetic activity. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 13/13721-8 - Estudo do envolvimento do sistema endocanabinóide do córtex pré-frontal medial ventral sobre a ingestão alimentar de ratos.
• Beneficiário: América Scopinho Augusto
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/00249-9 - Envolvimento da neurotransmissão opioidérgica da amígdala medial na mediação das respostas autonômicas e hormonais causadas pelo estresse de restrição em ratos
• Beneficiário: Aline Fassini
• Linha de fomento: Bolsas no Brasil - Doutorado