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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Purinergic receptor blockade in the retrotrapezoid nucleus attenuates the respiratory chemoreflexes in awake rats

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Barna, B. F. [1] ; Takakura, A. C. [2] ; Mulkey, D. K. [3] ; Moreira, T. S. [1]
Total Authors: 4
[1] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, Prof Lineu Prestes Av 1524, BR-05508000 Sao Paulo, SP - Brazil
[2] Univ Sao Paulo, Inst Biomed Sci, Dept Pharmacol, Prof Lineu Prestes Av 1524, BR-05508000 Sao Paulo, SP - Brazil
[3] Univ Connecticut, Dept Physiol & Neurobiol, Storrs, CT 06269 - USA
Total Affiliations: 3
Document type: Journal article
Source: ACTA PHYSIOLOGICA; v. 217, n. 1, p. 80-93, MAY 2016.
Web of Science Citations: 12

AimRecent evidence suggests that adenosine triphosfate (ATP)-mediated purinergic signalling at the level of the rostral ventrolateral medulla contributes to both central and peripheral chemoreceptor control of breathing and blood pressure: neurones in the retrotrapezoid nucleus (RTN) function as central chemoreceptors in part by responding to CO2-evoked ATP release by activation of yet unknown P2 receptors, and nearby catecholaminergic C1 neurones regulate blood pressure responses to peripheral chemoreceptor activation by a P2Y1 receptor-dependent mechanism. However, potential contributions of purinergic signalling in the RTN to cardiorespiratory function in conscious animals have not been tested. MethodsCardiorespiratory activity of unrestrained awake rats was measured in response to RTN injections of ATP, and during exposure to hypercapnia (7% CO2) or hypoxia (8% O-2) under control conditions and after bilateral RTN injections of P2 receptor blockers (PPADS or MRS2179). ResultsUnilateral injection of ATP into the RTN increased cardiorespiratory output by a P2-recepor-dependent mechanism. We also show that bilateral RTN injections of a non-specific P2 receptor blocker (pyridoxal-phosphate-6-azophenyl-2,4-disulfonate (PPADS) reduced the ventilatory response to hypercapnia (7% CO2) and hypoxia (8% O-2) in unanesthetized rats. Conversely, bilateral injections of a specific P2Y1 receptor blocker (MRS2179) into the RTN had no measurable effect on ventilatory responses elicited by hypercapnia or hypoxia. ConclusionThese data exclude P2Y1 receptor involvement in the chemosensory control of breathing at the level of the RTN and show that ATP-mediated purinergic signalling contributes to central and peripheral chemoreflex control of breathing and blood pressure in awake rats. (AU)

FAPESP's process: 09/54888-7 - Neural mechanisms involved on chemoreception
Grantee:Eduardo Colombari
Support type: Research Projects - Thematic Grants
FAPESP's process: 13/10573-8 - Ventral surface chemoreceptor neuronal mechanisms
Grantee:Thiago dos Santos Moreira
Support type: Regular Research Grants
FAPESP's process: 10/09776-3 - Neural mechanisms involved in expiratory rhythm generator: possible involvement of the retrotrapezoid nucleus and the parafacial region
Grantee:Ana Carolina Thomaz Takakura
Support type: Research Grants - Young Investigators Grants
FAPESP's process: 12/10337-0 - Neural mechanisms involved in purinergic signaling in the control of central and peripheral chemosensitivity
Grantee:Bárbara Falquetto
Support type: Scholarships in Brazil - Doctorate