Relationship between hydroxy fatty acids and prostaglandin E-2 in gingivaltissue

Bacterial hydroxy fatty acids and alpha-hydroxy fatty acids have been demon strated in complex lipid extracts df subgingival plaque and gingival tissue . However, little is known about the relationship between these hydroxy fat ty acids in plaque and gingival tissues or the significance of these comple x lipids in promoting inflammatory periodontal disease. The present study d etermined the percentages of ester-linked and amide-linked hydroxy fatty ac ids in complex lipids recovered from plaque and gingival tissue samples and the relationship between bacterial hydroxy fatty acids and alpha-hydroxy f atty acids in the lipid extracts. To evaluate a potential role for these hy droxy fatty acids in inflammatory periodontal disease, gingival tissue samp les were examined for a relationship between prostaglandin E-2 (PGE(2)) and hydroxy fatty acids recovered in gingival lipid. This investigation demons trated that alpha-hydroxy fatty acids are only ester linked in plaque lipid s but are largely amide linked in gingival tissue lipids. Furthermore, the level of alpha-hydroxy fatty acid in gingival lipid is directly related to the level of the bacterial hydroxy fatty acid 3-OH iso-branched C-17:0 (3-O H iC(17:0)) in the same lipid extract. However, the relationship between hy droxy fatty acids in gingival lipids does not parallel the fatty acid relat ionship observed in plaque lipids. Finally, alpha-hydroxy fatty acid levels in gingival tissue lipids correlate directly with the recovery of PGE(2) i n the same tissue samples. These results demonstrate that alpha-hydroxy fat ty acid levels in gingival lipids are directly related to both 3-OH iC(17:0 ) bacterial lipid levels and PGE(2) levels. These results indicate that in periodontal tissues there are unusual host-parasite interactions involving penetration of bacterial lipid in association with an altered gingival lipi d metabolism and prostaglandin synthesis.