Changes in polyamine metabolism during experimental periodontitis in dogs and the role of putrescine in recovery

Abstract

There are many reports showing a close relationship between polyamine metabolism and tissue growth or the recovery of damaged tissues, such as that occurring after partial hepatectomy. Therefore, it was proposed that the metabolism of polyamines might change in periodontitis induced by attaching surgical ligatures below the gingival margin of dog molars. One to two days after fixing the ligatures, the putrescine content and activity of ornithine decarboxylase in the tissue rose to about twice the control levels and then decreased gradually to control levels on day 7. No significant change in spermidine or spermine concentration was observed during this period. When the ligatures were removed on day 7, the putrescine content increased to about 2.5 times the normal level within 12 h. Ornithine decarboxylase activity changed in parallel with the change in putrescine content. Clinical and histopathological indications of periodontitis then started to decrease and had almost disappeared 2 weeks after removal of the ligatures. On the other hand, when the ligatures were removed on day 14, no significant increase in putrescine content was observed within 36 h and the rate of recovery from periodontitis was significantly slower than when the ligatures were removed on day 7. However, application of putrescine to the periodontal pocket immediately after removal of the ligatures on day 14 increased the rate of recovery, as determined by histological criteria. These findings suggest that putrescine or its metabolites are important in the process of recovery from periodontitis.