{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T08:03:35Z","timestamp":1780473815475,"version":"3.54.1"},"reference-count":0,"publisher":"Wiley","issue":"7","license":[{"start":{"date-parts":[[2002,7,1]],"date-time":"2002-07-01T00:00:00Z","timestamp":1025481600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Periodontology"],"published-print":{"date-parts":[[2002,7]]},"abstract":"<jats:p><jats:bold>Background:<\/jats:bold> Chemically modified tetracyclines (CMTs), devoid of antimicrobial activity, inhibit pathologically elevated collagenase activity both in vivo and in vitro. In the current study, doxycycline and 5 different CMTs were tested to prevent matrix metalloproteinase (MMP)\u2010dependent periodontal tissue breakdown in an animal model of periodontitis.<\/jats:p><jats:p><jats:bold>Methods:<\/jats:bold> Adult male rats received intragingival injections with either 10 \u00b5l of physiologic saline or <jats:italic>Escherkhia coli<\/jats:italic> endotoxin (1 mg\/ml) every other day for 6 days and were distributed into 8 treatment groups (12 rats\/group): saline (S), endotoxin alone (E), E + CMT\u20101, E + CMT\u20103, E + CMT\u20104, E + CMT\u20107, E + CMT\u20108, and doxycycline. All animals were treated daily with 1 ml of 2% carboxymethyl cellulose (CMC) alone or containing one of the above\u2010mentioned CMTs (2 mg\/day) orally. The gingival tissues were removed, extracted, and assayed for gelatinase (GLSE). Some rat maxillary jaws from each treatment group were fixed in buffered formalin and processed for histology and immunohistochemistry for the cytokines tumor necrosis factor (TNF), interleukin (lL)\u20101, and IL\u20106, and MMP\u20102 and MMP\u20109.<\/jats:p><jats:p><jats:bold>Results:<\/jats:bold> Endotoxin injection induced elevated GLSE activity (functional assay and osteoclast\u2010mediated bone resorption), the former identified as predominantly MMP\u20109 (92 kDa GLSE) by gelatin zymography. All 6 tetracyclines (2 mg\/day) inhibited periodontal breakdown in the following order of efficacy: CMT\u20108 &gt; CMT\u2010 1 &gt; CMT\u20103 &gt; doxycycline &gt; CMT\u20104 &gt; CMT\u20107. Immunohistochemistry was positive for TNF, IL\u2010 1, and IL\u20106 in the inflammatory cells from untreated endotoxin rat tissues, whereas treatment with CMTs decreased the number of immuno\u2010positive stained cells for cytokines and MMPs. The in vivo efficacy of these drugs varied with CMT structure and was significantly correlated with bone resorption: r<jats:sup>2<\/jats:sup> = \u20100.77, <jats:italic>P<\/jats:italic> &lt;0.01; gelatinase inhibitory activity: r<jats:sup>2<\/jats:sup> = \u22120.84, <jats:italic>P<\/jats:italic> &lt;0.01; and serum drug concentrations.<\/jats:p><jats:p><jats:bold>Conclusion:<\/jats:bold> Since both conventional (antimicrobial) and non\u2010antimicrobial tetracyclines inhibited periodontal bone resorption induced by endotoxin injection, MMP\u2010mediated bone loss in this model can be prevented by inhibition of MMPs. <jats:italic>J Periodontol 2002;73:726\u2010734.<\/jats:italic><\/jats:p>","DOI":"10.1902\/jop.2002.73.7.726","type":"journal-article","created":{"date-parts":[[2005,2,2]],"date-time":"2005-02-02T07:23:52Z","timestamp":1107329032000},"page":"726-734","source":"Crossref","is-referenced-by-count":89,"title":["Inhibition of Matrix Metalloproteinase\u2010Mediated Periodontal Bone Loss in Rats: A Comparison of 6 Chemically Modified Tetracyclines"],"prefix":"10.1002","volume":"73","author":[{"given":"Nungavarum S.","family":"Ramamurthy","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Barry R.","family":"Rifkin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert A.","family":"Greenwald","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jing\u2010wen","family":"Xu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu","family":"Liu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gloza","family":"Turner","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lorne M.","family":"Golub","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anthony T.","family":"Vernillo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2002,7]]},"container-title":["Journal of Periodontology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/aap.onlinelibrary.wiley.com\/doi\/pdf\/10.1902\/jop.2002.73.7.726","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,19]],"date-time":"2025-10-19T09:52:29Z","timestamp":1760867549000},"score":1,"resource":{"primary":{"URL":"https:\/\/aap.onlinelibrary.wiley.com\/doi\/10.1902\/jop.2002.73.7.726"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2002,7]]},"references-count":0,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2002,7]]}},"alternative-id":["10.1902\/jop.2002.73.7.726"],"URL":"https:\/\/doi.org\/10.1902\/jop.2002.73.7.726","archive":["Portico"],"relation":{},"ISSN":["0022-3492","1943-3670"],"issn-type":[{"value":"0022-3492","type":"print"},{"value":"1943-3670","type":"electronic"}],"subject":[],"published":{"date-parts":[[2002,7]]}}}