Effects of lipoxygenase on primary periodontitis
| Project/Area Number |
01571046
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Conservative dentistry
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| Research Institution | Hiroshima University |
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Principal Investigator |
OKAMOTO Hiroshi Hiroshima Univ. Sch. of Dentistry Professor, 歯学部, 教授 (50028742)
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| Co-Investigator(Kenkyū-buntansha) |
DOHI Toshihiro Hiroshima Univ. Sch. of Dentistry Associate professor, 歯学部, 助教授 (00034182)
TSUJIMOTO AKira Hiroshima Univ. Sch. of Detistry Professor, 歯学部, 教授 (90034181)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1990: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1989: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | 12-Hydroxyeicosatetraenoic acid / Chemotaxis / 12-hydroxyeicosatetraenoic acid |
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| Research Abstract |
<Purpose>
It has been demonstrated that 12-hydroxyeicosatetraenoic acid(12-HETE), which is 12-lipoxygenase(12-HETE)metabolites of arachidonic acid, is produced in gingival tissues. 12-HETE, which has many biological activities, i. e. degranulation, chemotactic activity and bone resorption. In this study, we investisted the effects of 12-HETE on human leukocytes, especially, the mechanisms of 12-HETE induced increase of intracellular Ca^<2+> concentration([Ca2, ]i).
<Methods & Results>
12-Lipoxygenase activity of various tissues in rat was measured by thin layer autoradlogram. The chemokinetic activity of 12-HETE for human peripheral blood polymorphonuclear leukocytes(PMNS)was examined in modified Boyden chamber assay. Intracellular free calcium was monitored using the fluorescent probe fura-2.
12-Lipoxygenase activity in rat gingiva was much higher than any other tissues. Both 12-HETE and N-formyl-methionyl-leucyl-phenylalanine(FMLP)stimulated chemokinetic movement of hurffan PMNs in a dose dependent manner. However, 12-HETE suppressed chemokinetic movement stimulated by fMLP in a dose dependent manner. 12HETE induced the increase of[Ca^<2+>i in human PMNs in a dose dependent manner and suppressed the[Ca^<2+>]i increase induced by fMLP. N-BOC-MLP(10^<-5>M), FMLP receptor antagonist, inhibited the increase of[Ca^<2+>]i by fMLP, but not by 12-HETE. 12-HETEinduced the increase of[Ca^<2+>], Was abolished by pretreatment with pertussis toxin. The increase in[Ca^<2+>, ]i induced by 12-HETE was inhibited by U-73122, a specific phospholipase C(PLC)inhibitor. 12-HETE stimulated the production of inositol 1, 4, 5trisphosphate.
<Conclusions>
These results suggest that 12-HETE has chemokinetic activity for human PMNs and have interaction with another chemotactic factor. The mechanisms for 12-HETE to increase[Ca^<2+>]i may involve PLC activation through the guanin-nucleotide-binding protein, resulting in an increase in the phosphatidylinositol turnover.
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Report
(3 results)
Research Products
(3 results)
