17
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Inhibitory interactions between 5-HT3 and P2X channels in submucosal neurons.

      American Journal of Physiology - Gastrointestinal and Liver Physiology
      Adenosine Triphosphate, pharmacology, Animals, Calcium, Cesium, Drug Interactions, Drug Tolerance, Electric Conductivity, Female, GTP-Binding Proteins, physiology, Guinea Pigs, Jejunum, Kinetics, Magnesium, Male, Muscle, Smooth, innervation, Neurons, Phosphoproteins, metabolism, Phosphorylation, Receptors, Purinergic P2, drug effects, Receptors, Purinergic P2X, Receptors, Serotonin, Receptors, Serotonin, 5-HT3, Serotonin

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Inhibitory interactions between 5-HT subtype 3 (5-HT(3)) and P2X receptors were characterized using whole cell recording techniques. Currents induced by 5-HT (I(5-HT)) and ATP (I(ATP)) were blocked by tropisetron (or ondansetron) and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid, respectively. Currents induced by 5-HT + ATP (I(5-HT+ATP)) were only as large as the current induced by the most effective transmitter, revealing current occlusion. Occlusion was observed at membrane potentials of -60 and 0 mV (for inward currents), but it was not present at +40 mV (for outward currents). Kinetic and pharmacological properties of I(5-HT+ATP) indicate that they are carried through 5-HT(3) and P2X channels. Current occlusion occurred as fast as activation of I(5-HT) and I(ATP), was still present in the absence of Ca(2+) or Mg(2+), after adding staurosporine, genistein, K-252a, or N-ethylmaleimide to the pipette solution, after substituting ATP with proportional to, beta-methylene ATP or GTP with GTP-gamma-S in the pipette, and was observed at 35 degrees C, 23 degrees C, and 8 degrees C. These results are in agreement with a model that considers that 5-HT(3) and P2X channels are in functional clusters and that these channels might directly inhibit each other.

          Related collections

          Author and article information

          Comments

          Comment on this article