Grant-in-Aid for Scientific Research (A)
|Allocation Type||Single-year Grants|
|Research Institution||Tokyo Medical and Dental University|
TOKORO Takashi Tokyo Med & Dent.Uni, Medicine, Professor, 医学部, 教授 (20013865)
OHIDA Shin-ichiro Tokyo Med & Dent.Uni, Dentistry, 歯学部, 助手 (10114745)
SHIMOKAWA M.toyatn Tokyo Med & Dent.Uni, Dentistry, Ass.Prof., 歯学部, 助教授 (80014257)
SEKO Yuko Tokyo Med & Dent.Uni, Medicine, 医学部, 助手
OHNO Kyoko Tokyo Med & Dent.Uni, Medicine, Lecturer, 医学部, 講師 (30262174)
森田 博之 東京医科歯科大学, 医学部, 講師 (80230126)
|Project Period (FY)
1995 – 1997
Completed(Fiscal Year 1997)
|Budget Amount *help
¥5,800,000 (Direct Cost : ¥5,800,000)
Fiscal Year 1997 : ¥2,600,000 (Direct Cost : ¥2,600,000)
Fiscal Year 1996 : ¥3,200,000 (Direct Cost : ¥3,200,000)
|Keywords||Experimental Myopia / Sclera / vetina / dopamine / growth factor / differentical display / mechanical strain / differential display / 青色光 / 視性刺激遮断 / 細膜 / 網膜色素上皮 / TGFβ / レチノイン酸|
(1) Unknown substances regulating ocular growth
Differential display cloning was conducted between the normal retina and the form-deprived retina. 46 bands were lsolated which were expressed more strongly in the normal retina than in the deprived retina. Following reamplification, dot blot differential hybridization and northern blot selected 3 cDNA clones. Sequence homology analysis revealed that those 3 cDNA clones have unknown sequences. Now, we are investigating about those 3 cDNA clones.
(2) Involvement of growth factors and retinoic acid
Immunohistochemical analyzes of experimental myopic chickens revealed that TGF-beta and IGF II are increased in the myopic sclera. Biochemical analyzes showed that TGF-beta is increased and bFGF is decreased in the myopic sclera and that TGF-beta is also increased in the myopic retina-chorold. RT-PCR-ELISA revealed that expression of retinoic acid receptor-beta is increased in the myopic sclera and HPLC analysis showed that retinoic acid is increase
d in the myopic retina.
Tissue culture experiments showed that the retinal pigment epithelium (RPE) releases some growth regulating substances.
(3) Regulation of growth regulating mechanism of theRPE
-relationship to the blue light exposure-
Previous reports showed that visible light of short wave length "blue light" is toxic to the retina. But the mechanism of the toxicity has been unclear. We established an in virto model of exposure of blue light to the RPE and investigated the morphology of degeneration of the RPE by blue light in detail. We are investigating fuctional changes of the RPE by blue light exposure.
(4) Involvement of retinal dopamine in the roles of growth factors
Retinal dopamine has been reported to be decreased in the myopic eye. We demonstrated that apomorphine, dopamine agonist, inhibits growth stimulating effects of RPE on scleral cells in vitro. Now, we are investigating about roles of Muller cells. At first, we revealed that dopamine inhibits cell growth of Muller cells.
(5) Involvement of mechanical strain in the roles of growth factors
Ocular hypertension and accommodation have been reported to play a role in the ocular enlargement. We investigated the effects of mechanical strain on the biochemical changes of the scleral cells and the RPE cells in vitro. Mechanical strain affected cell growth of scleral cells and the release of growth factors from the RPE cells. Less