Opioid mu-receptors in the rostral medullary raphe modulate hypoxia-induced hyperpnea in unanesthetized rats
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Data
2012-03-01
Autores
Dias, M. B.
Nucci, T. B.
Branco, L. G. S.
Gargaglioni, L. H. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Wiley-Blackwell
Resumo
Aim: It has been suggested that the medullary raphe (MR) plays a key role in the physiological responses to hypoxia. As opioid mu-receptors have been found in the MR, we studied the putative role of opioid mu-receptors in the rostral MR (rMR) region on ventilation in normal and 7% hypoxic conditions.Methods: We measured pulmonary ventilation ((V) over dotE) and the body temperatures (Tb) of male Wistar rats before and after the selective opioid l-receptor antagonist CTAP ( d-Phe-Cys-Tyr-d-Trp-Arg-Thr-Pen-Thr-NH2, cyclic, 0.1 mu g per 0.1 mu L) was microinjected into the rMR during normoxia or after 60 min of hypoxia.Results: The animals treated with intra-rMR CTAP exhibited an attenuation of the ventilatory response to hypoxia ( 430 +/- 86 mL kg) 1 min) 1) compared with the control group ( 790 +/- 82 mL kg) 1 min) 1) ( P < 0.05). No differences in the Tb were observed between groups during hypoxia.Conclusion: These data suggest that opioids acting on l-receptors in the rMR exert an excitatory modulation of hyperventilation induced by hypoxia.
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Palavras-chave
Control of breathing, opiates, Pulmonary ventilation, raphe nuclei
Como citar
Acta Physiologica. Malden: Wiley-blackwell, v. 204, n. 3, p. 435-442, 2012.