title: Neither nociceptin nor its receptor are present in human synovial fluid or tissue.
abstract: Our aim was to identify the nociceptin receptor and its endogenous ligand, nociceptin, in human peripheral tissue. Synovial tissue was obtained from 11 patients (ASA I-III, 66-84 yr) undergoing elective total knee replacement. Synovial fluid was obtained from another 10 patients (ASA I-III, 57-81 yr). Fluid was mixed with trifluoroacetic acid and the tissue with isopentone before freezing at -70 degrees C. Nociceptin receptor identification was performed using a [3H]nociceptin binding assay and nociceptin detection by radioimmunoassay. There was no specific [3H]nociceptin binding to knee synovial tissue and radioimmunoassay did not detect nociceptin. Neither the nociceptin receptor nor nociceptin was found in human synovial tissue or fluid.
authors.affiliation: University Department of Anaesthesia and Pain Management, Leicester Royal Infirmary, UK.
authors.forename: N
authors.initials: N
authors.lastname: Kumar
authors.forename: D
authors.initials: D
authors.lastname: Smart
authors.forename: S
authors.initials: S
authors.lastname: Mason
authors.forename: A T
authors.initials: AT
authors.lastname: McKnight
authors.forename: D J
authors.initials: DJ
authors.lastname: Rowbotham
authors.forename: D G
authors.initials: DG
authors.lastname: Lambert
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000601:surgery; D019645:Arthroplasty, Replacement, Knee; D006801:Humans; D008875:Middle Aged; D018847:Opioid Peptides / Q000032:analysis*; D020370:Osteoarthritis, Knee / Q000378:metabolism* / Q000601:surgery; D011863:Radioimmunoassay; D011957:Receptors, Opioid / Q000378:metabolism*; D013582:Synovial Fluid / Q000378:metabolism; D013583:Synovial Membrane / Q000378:metabolism*; D000094942:Nociceptin Receptor; D000097629:Nociceptin
chemical_list: D018847:Opioid Peptides; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C000722283:OPRL1 protein, human