Nociceptin/orphanin FQ stimulates extracellular acidification and desensitization of the response involves protein kinase C

Gang Pei, Kun Ling, Lu Pu, Martin D. Cunningham, Lan Ma

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19 Scopus citations


A Chinese hamster ovary (CHO) cell line, CHO-ORL1, stably expressing human opioid receptor-like receptor 1 (ORL1) has been used to determine ORL1-mediated signaling events using microphysiometry. Nociceptin/orphanin FQ (N/OFQ), a specific endogenous agonist of ORL1, induced an increase in extracellular acidification rate (ECAR) in CHO-ORL1 cells. The ECAR response stimulated by N/OFQ was concentration-dependent and pertussis toxin-sensitive. Repeated exposures of the cells to N/OFQ caused desensitization of ORL1. The ECAR response was recovered at the half-life of approximately 12 min after the initial challenge. Pretreatment with inhibitor of cAMP-dependent kinase did not affect desensitization of ORL1. However, specific inhibitors for protein kinase C almost abolished N/OFQ-induced desensitization of extracellular acidification responsiveness, indicating the involvement of protein kinase C in the process.

Original languageEnglish (US)
Pages (from-to)253-256
Number of pages4
JournalFEBS Letters
Issue number1
StatePublished - Jul 21 1997



  • Extracellular acidification
  • Nociceptin/orphanin FQ
  • Opioid receptor
  • Opioid receptor-like receptor 1 (ORL)
  • Protein kinase C
  • Receptor desensitization

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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