Expression of P2X3 and P2X5 Myenteric Receptors Varies During the Intestinal Postnatal Development in the Guinea Pig

• Published in: Cellular and molecular neurobiology 2014, Vol.34 (5), p.727-736
• Main Authors: Loera-Valencia, Raúl, Jiménez-Vargas, Néstor N., Villalobos, Egina C., Juárez, Esri H., Lomas-Ramos, Telma Liliana, Espinosa-Luna, Rosa, Montaño, Luis M., Huizinga, Jan D., Barajas-López, Carlos
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Biomedicine; Cell Biology; Neurobiology; Neurosciences; Original Research
• ISSN: 0272-4340; 1573-6830
• DOI: 10.1007/s10571-014-0055-8

P2X 3 receptor expression in various tissues appears to be modulated by age. In the present study, we used single cell RT-PCR to determine the number of P2X 3 positive myenteric neurons at different stages of guinea pig postnatal development, and we tested if similar changes also occur to other myenteric P2X receptors. Moreover, we carried out whole-cell recordings using Patch Clamp techniques to determine possible changes in P2X receptors sensitivity to ATP and α,β-methylene ATP (α,β-meATP) between newborn and adult animals. Our data indicate that P2X 3 subunit transcripts are present in a larger number of myenteric neurons from newborn guinea pigs whereas P2X 5 mRNA is found more frequently in adults. Expression of P2X 2 and P2X 4 transcripts does not change during postnatal development. In newborn animals, virtually all neurons expressing P2X 3 also expressed P2X 2 transcripts. This is important because these two subunits are known to form heteromeric channels. ATP potency to activate P2X receptors in neurons of both newborn and adult animals was the same. α,β-meATP, a known P2X 3 receptor agonist, induces only a marginal current despite the fact of the higher presence of P2X 3 subunits in newborns. These findings imply that P2X 3 subunits are mainly forming heteromeric, α,β-meATP insensitive channels perhaps because P2X 3 contributes with only one subunit to the heterotrimers while the other subunits could be P2X 2 , P2X 4 , or P2X 5 .