title: Heterogeneity of the functional expression of P2X3 and P2X2/3 receptors in the primary nociceptive neurons of rat.
abstract: The properties and functional expression of the purinergic receptors in small (nociceptive) neurons acutely isolated from the DRG of rat were studied using whole-cell patch-clamp recording. The responses of small DRG neurons to ATP exhibited diverse kinetics and could be subdivided into three types: rapid, slow and mixed kinetics responses. Their affinities to agonists allowed to identify the responsible receptors as P2X3 ("fast") and heteromeric P2X2/3 ("slow") subtypes. The expression of different responses dramatically varied both on the neuron-to-neuron and animal-to-animal basis. Out of 744 neurons tested 24% of cells demonstrated predominance of functional P2X2/3 receptors, 44% had mixed representation and in 32% of cells P2X3 receptors dominated. All the animals tested (110) could be subdivided into 3 groups: in 19% of animals the response of each cell to ATP was mediated by P2X2/3 receptors, both types of ATP-evoked currents were found in 58% of animals and only in 23% of the animals P2X3 receptors dominated. Our results argue with exclusive role of P2X3 receptors in purinergic signaling in primary nociceptive neurons.
authors.affiliation: Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kyiv, Ukraine.
authors.lastname: Pankratov YuV
authors.forename: U V
authors.initials: UV
authors.lastname: Lalo
authors.forename: A N
authors.initials: AN
authors.lastname: Dashkin
authors.forename: A
authors.initials: A
authors.lastname: Krishtal
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D009474:Neurons / Q000378:metabolism* / Q000502:physiology; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D018048:Receptors, Purinergic P2 / Q000187:drug effects / Q000378:metabolism*; D058476:Receptors, Purinergic P2X2; D058477:Receptors, Purinergic P2X3
chemical_list: C546403:P2rx2 protein, rat; C546410:P2rx3 protein, rat; D018048:Receptors, Purinergic P2; D058476:Receptors, Purinergic P2X2; D058477:Receptors, Purinergic P2X3; D000255:Adenosine Triphosphate