{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,12]],"date-time":"2025-09-12T19:07:00Z","timestamp":1757704020222},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"1","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1992,5,15]]},"abstract":"<jats:p>Binding of 3H-labelled platelet-activating factor ([3H]PAF) to guinea-pig tracheal epithelial cells was time-dependent, reversible and saturable. Scatchard analysis of the saturation-binding data indicated that [3H]PAF bound to one class of specific binding sites with high affinity (KD = 4.3 +\/- 0.03 nM; Bmax. = 0.172 +\/- 0.02 fmol\/10(5) cells; n = 3). Unlabelled PAF competitively and selectively inhibited the specific binding of [3H]PAF with 50% inhibition at 4.8 +\/- 0.07 nM (n = 3). SR 27417, the first member of a newly developed PAF antagonist series, competitively displaced [3H]PAF from its binding sites on guinea-pig tracheal epithelial cells with a Ki of 100 +\/- 3 pM (n = 3). Studies carried out in parallel demonstrated that SR 27417 was 40 times more potent than C16-PAF itself and more than 100-fold as active as the best synthetic PAF-receptor antagonist yet described. [3H]SR 27417 displayed high-affinity, specific, reversible as well as saturable binding to a single class of binding sites on tracheal epithelial cells (KD = 94 +\/- 7 pM; Bmax. = 0.181 +\/- 0.04 fmol\/10(5) cells; n = 3). C16-PAF, lyso-PAF, enantio-PAF, SR 27417 and other PAF-receptor antagonists had Ki values which were nearly identical for both [3H]PAF and [3H]SR 27417, demonstrating that in guinea-pig tracheal epithelial cells they have the same binding sites. In conclusion, these data suggest that tracheal epithelial cells contain PAF-specific receptors and indicate that SR 27417 is an extremely potent PAF-receptor antagonist, as well as being a suitable radioligand for labelling PAF receptors on intact cells.<\/jats:p>","DOI":"10.1042\/bj2840201","type":"journal-article","created":{"date-parts":[[2015,8,13]],"date-time":"2015-08-13T21:20:57Z","timestamp":1439500857000},"page":"201-206","update-policy":"http:\/\/dx.doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Characterization of specific binding sites of 3H-labelled platelet-activating factor ([3H]PAF) and a new antagonist, [3H]SR 27417, on guinea-pig tracheal epithelial cells"],"prefix":"10.1042","volume":"284","author":[{"given":"J M","family":"Herbert","sequence":"first","affiliation":[{"name":"Haemobiology Research Department, Sanofi Recherche, 195 Route d'Espagne, 31036 Toulouse Cedex, France."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/284\/1\/201\/606462\/bj2840201.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/284\/1\/201\/606462\/bj2840201.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,24]],"date-time":"2021-11-24T01:01:07Z","timestamp":1637715667000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/284\/1\/201\/37223\/Characterization-of-specific-binding-sites-of-3H"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,5,15]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1992,5,15]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2840201","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,5,15]]}}}