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Guinea-pig sympathetic neurons express varying proportions of two distinct P2X receptors.
J Physiol. 2000 Mar 01; 523 Pt 2:391-402.JP

Abstract

1. Characterization of P2X receptors on neurons of guinea-pig superior cervical ganglion (SCG) has been carried out using a whole-cell voltage-clamp technique. 2. Application of ATP and alpha,beta-methylene ATP (alphabeta-MeATP) produced fast activating inward currents, which desensitized slowly. The maximum response to alphabeta-MeATP was 36 +/- 23 % (range 0.1-100 %) of that evoked by ATP in the same cell. 3. Co-application of alphabeta-MeATP (300 microM) with ATP (300 microM) produced a response that was 97 +/- 1 % of that given by ATP alone. Following desensitization with alphabeta-MeATP, the decrease in response to ATP was equal to the absolute reduction in response to alphabeta-MeATP in the same cell. 4. The concentration-response curve for alphabeta-MeATP had an EC50 of 42 microM and a Hill coefficient of 1.17. For cells where the ratio of alphabeta-MeATP/ATP currents at 100 microM was < 0.1, the ATP concentration-response curve had an EC50 of 56 microM and a Hill coefficient of 1.95. However, in cells where the ratio was > 0.7, the curve had an EC50 of 60 microM and a Hill coefficient of 0.97. 5. The response to 100 microM alphabeta-MeATP was inhibited by 2' (or 3')-O-trinitrophenyl-ATP (TNP-ATP) with an IC50 of 70 nM. However, on cells where the ratio of alphabeta-MeATP/ATP currents was < 0.1, ATP was inhibited by TNP-ATP with an IC50 of 522 nM. 6. Immunohistochemical staining with antibodies raised against rat P2X2 and P2X3 epitopes suggested that both subunits were expressed by guinea-pig SCG neurons. 7. We conclude that varying proportions of two distinct P2X receptors coexist on the cell bodies of individual guinea-pig SCG neurons, which may correspond to homomeric P2X2 and heteromeric P2X2/3 receptors.

Authors+Show Affiliations

Autonomic Neuroscience Institute, Department of Anatomy and Developmental Biology, Royal Free and University College Medical School, Rowland Hill Street, London NW3 2PF, UK. y.zhong@ucl.ac.ukNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

10699083

Citation

Zhong, Y, et al. "Guinea-pig Sympathetic Neurons Express Varying Proportions of Two Distinct P2X Receptors." The Journal of Physiology, vol. 523 Pt 2, 2000, pp. 391-402.
Zhong Y, Dunn PM, Burnstock G. Guinea-pig sympathetic neurons express varying proportions of two distinct P2X receptors. J Physiol (Lond). 2000;523 Pt 2:391-402.
Zhong, Y., Dunn, P. M., & Burnstock, G. (2000). Guinea-pig sympathetic neurons express varying proportions of two distinct P2X receptors. The Journal of Physiology, 523 Pt 2, 391-402.
Zhong Y, Dunn PM, Burnstock G. Guinea-pig Sympathetic Neurons Express Varying Proportions of Two Distinct P2X Receptors. J Physiol (Lond). 2000 Mar 1;523 Pt 2:391-402. PubMed PMID: 10699083.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Guinea-pig sympathetic neurons express varying proportions of two distinct P2X receptors. AU - Zhong,Y, AU - Dunn,P M, AU - Burnstock,G, PY - 2000/3/4/pubmed PY - 2000/4/15/medline PY - 2000/3/4/entrez SP - 391 EP - 402 JF - The Journal of physiology JO - J. Physiol. (Lond.) VL - 523 Pt 2 N2 - 1. Characterization of P2X receptors on neurons of guinea-pig superior cervical ganglion (SCG) has been carried out using a whole-cell voltage-clamp technique. 2. Application of ATP and alpha,beta-methylene ATP (alphabeta-MeATP) produced fast activating inward currents, which desensitized slowly. The maximum response to alphabeta-MeATP was 36 +/- 23 % (range 0.1-100 %) of that evoked by ATP in the same cell. 3. Co-application of alphabeta-MeATP (300 microM) with ATP (300 microM) produced a response that was 97 +/- 1 % of that given by ATP alone. Following desensitization with alphabeta-MeATP, the decrease in response to ATP was equal to the absolute reduction in response to alphabeta-MeATP in the same cell. 4. The concentration-response curve for alphabeta-MeATP had an EC50 of 42 microM and a Hill coefficient of 1.17. For cells where the ratio of alphabeta-MeATP/ATP currents at 100 microM was < 0.1, the ATP concentration-response curve had an EC50 of 56 microM and a Hill coefficient of 1.95. However, in cells where the ratio was > 0.7, the curve had an EC50 of 60 microM and a Hill coefficient of 0.97. 5. The response to 100 microM alphabeta-MeATP was inhibited by 2' (or 3')-O-trinitrophenyl-ATP (TNP-ATP) with an IC50 of 70 nM. However, on cells where the ratio of alphabeta-MeATP/ATP currents was < 0.1, ATP was inhibited by TNP-ATP with an IC50 of 522 nM. 6. Immunohistochemical staining with antibodies raised against rat P2X2 and P2X3 epitopes suggested that both subunits were expressed by guinea-pig SCG neurons. 7. We conclude that varying proportions of two distinct P2X receptors coexist on the cell bodies of individual guinea-pig SCG neurons, which may correspond to homomeric P2X2 and heteromeric P2X2/3 receptors. SN - 0022-3751 UR - https://www.unboundmedicine.com/medline/citation/10699083/Guinea_pig_sympathetic_neurons_express_varying_proportions_of_two_distinct_P2X_receptors_ L2 - https://onlinelibrary.wiley.com/resolve/openurl?genre=article&amp;sid=nlm:pubmed&amp;issn=0022-3751&amp;date=2000&amp;volume=523&amp;spage=391 DB - PRIME DP - Unbound Medicine ER -