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Activation of NTS A 2a Adenosine Receptors Impairs Cardiopulmonary Chemoreflex Control of Renal (RSNA), Adrenal (ASNA) and Lumbar (LSNA) Sympathetic Nerve Activity
Author(s) -
Minic Zeljka,
O'Leary Donal S.,
Scislo Tadeusz J.
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.624.11
Subject(s) - adenosine , chemistry , adenosine receptor , endocrinology , stimulation , adenosine a2a receptor , medicine , agonist , receptor , chemoreceptor , adenosinergic
Activation of NTS A 2a adenosine receptors increases ASNA, decreases RSNA and does not alter LSNA ( Clin Exp Physiol Pharmacol 28: 120–124, 2001). A similar pattern of regional sympathetic responses was occasionally observed following activation of cardiopulmonary chemoreceptors. As A 2a adenosine receptors may facilitate neurotransmitter release it was likely that these receptors may facilitate the cardiopulmonary chemoreflex. In the present study we compared the regional sympathetic responses evoked by right atrial injections of 5HT 3 receptor agonist, phenylbiguanide (PBG, 1–8 μg/kg), before and after stimulation of NTS A 2a adenosine receptors (microinjections of CGS21680 , 20 pmol/50 nl) in urethane/chloralose anesthetized rats (n=7). Activation of cardiopulmonary chemoreceptors evoked differential, dose dependent sympathoinhibition RSNA>ASNA>LSNA). Surprisingly, the responses in all sympathetic outputs (Δ%) were similarly attenuated following stimulation of NTS A 2a adenosine receptors (−95.5±1.8 vs. −60.3±5.3, −74.9±7.1 vs. −44.6±8.6, −56.4±3.6 vs. −34.61±5.6, for RSNA, ASNA and LSNA, respectively, at the maximal dose of PBG). We conclude that A 2a adenosine receptors may facilitate NTS neurons/terminals which inhibit cardiopulmonary chemoreflex pathway. NIH HL‐67814