| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Shozo Tokushima University, Biochemistry, Professor, 医学部, 教授 (50025607)
MUROTA Sei-etsu Tokyo Medical and Dental University, Physiological chemistry, Porfessor, 歯学部, 教授 (50072989)
SHIMIZU Takao Tohoku University, Biochemistry, Professor, 医学部, 教授 (80127092)
OMATA Ken Tohoku University, Hospital, Lecturer, 医学部・附属病院, 講師 (50194634)
OHUCHI Kazuo Tohoku University, Biochemistry, Professor, 薬学部, 教授 (20006357)
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| Research Abstract |
(1) We measured the urinary levels of prostacyclin (PGI_2) metabolites, thromboxane A_2 (TXA_2) metabolites, and 8-isoprostane in the patients with hyperlipidemia. Imbalance of the TXA_2/PGI_2 production was suggested in these patients with the progress of the disease, taking their serum lipids levels into consideration, It is also suggested that eicosapentaenoic acid administration influenced their TXA_2, PGI_2, and 8-isoprostane production. Moreover, imbalance of the TXA_2/PGI_2 production was observed in diabetics and in some cases with abnormal pregnancy such as gestational diabetes mellitus or intrauterine growth retardation.
(2) It was indicated that the anti-inflammatory action in COX-2 inhibitors in acute inflammatory model was based on the inhibition of the PGE_2 production with COX-2, and that the suppression of the gene expression of PLA_2 and COX-2 were not so important for the suppression of the plasma exudation observed in the treatment with dexamethasone.
Not COX-1 but COX
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-2 facilitated the vascularization through the regulation of the PG production in the vascularization model, It was also indicated that the induced VEGF actually influenced the vascularization in this model.
We established a system for the measurement of the COX activity in lived cells, noticing that COX possesses the peroxidase activity in addition to the COX activity, With this system, we showed that only COX-2 utilized the endogenous arachidonic acid and that NO significantly suppressed the COX-2 activity. COX-1 was induced by phorbol ester in human megakaryoblast leukemia cells CMK.Hemopoietic type of the PGD synthetase, which was not identified in platelets, was identified in the CMK cells. COX-2 was significantly induced by TNFalpha in murine osteoblast cells MC3T3-E1, It was indicated that NF-kappaB and NFIL-6 played roles as the transcription factors in the course of the induction.
(3) We established the quantitative methods of the leukotriene (LT) B_4 ; the radio immunoassay system using monoclonal antibody to LTB_4, the convenient enzyme-linked immunosorbent assay system using urinary samples, and the microdetermination system using LC/MS with ESI ion source.
Patients with asthma showed significantly high levels of LTE_4 and 11beta-PGF_<2a> in urine compared with those with the healthy volunteers, Patients with aspirin-induced asthma showed greatly high LTE_4 levels in urine, Significantly high 11beta-PGF_<2a> levels were observed in the urine from the patients with pulmonary emphysema.
We revealed that troglitazone, a novel antidiabetics, had LT-production suppressive action in the rat mast cell line RBL-2H3. We also revealed the biochemical aspects of the LTB_4 receptor that we succeeded in the cloning, When the LTB_4 gene expressed in CHO cells, it induced the inhibition of adenylate cyclase activity, increase in the concentration of the intracellular calcium, and it influenced to the wondering cell activity. Less
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