title: Noradrenaline stimulates ATP release from DRG neurons by targeting beta(3) adrenoceptors as a factor of neuropathic pain.
abstract: Noradrenaline (NA), released in association with sympathetic nerve sprouting into the dorsal root ganglion (DRG) after peripheral nerve injury, may enhance neuropathic pain. ATP serves as a pain mediator; however, NA-regulated ATP mobilizations in the DRG is far from understanding. In the present study, we analyzed ATP mobilizations in acutely dissociated rat DRG neurons by recording single-channel currents through P2X receptor channels as an ATP biosensor in an outside-out patch-clamp configuration and by monitoring real-time enzymatic NADPH fluorescent imaging, and examined the role for beta(3) adrenoceptors in allodynia using an in vivo rat model. We show here that NA stimulates ATP release from DRG neurons as mediated via beta(3) adrenoceptors linked to G(s) protein involving PKA activation, to cause allodynia. This represents a fresh regulatory pathway for neuropathic pain relevant to noradrenergic transmission in the DRG.
authors.affiliation: Division of Bioinformation, Department of Physiology, Hyogo College of Medicine, Mukogawa-cho, Nishinomiya, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kanno
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yaguchi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nishizaki
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D058673:Adrenergic beta-3 Receptor Antagonists; D000818:Animals; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D005727:Ganglia, Spinal / Q000166:cytology*; D015640:Ion Channel Gating / Q000187:drug effects; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009638:Norepinephrine / Q000494:pharmacology*; D010146:Pain / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D022702:Receptors, Adrenergic, beta-3 / Q000378:metabolism*
chemical_list: D058673:Adrenergic beta-3 Receptor Antagonists; D022702:Receptors, Adrenergic, beta-3; D000255:Adenosine Triphosphate; D017868:Cyclic AMP-Dependent Protein Kinases; D009638:Norepinephrine