1992 Fiscal Year Final Research Report Summary
Studies on the electrolyte transport in corneal cells.
| Project/Area Number |
03044087
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Kyoto University |
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Principal Investigator |
HONDA Yoshihito Kyoto University,, 医学部, 教授 (90026930)
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| Co-Investigator(Kenkyū-buntansha) |
P.S.REINACH ジョージア医科大学, 準教授
TANIHARA Hidendbu Kyoto University, 保健診療所, 助手 (60217148)
YOSHIMURA Nagahisa Kyoto University, 医学部, 講師 (70211662)
REINACH P.S. Medical College of Georgia
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| Project Period (FY) |
1992 – 1994
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| Keywords | Corneal endothelial cells / corneal epithelial cells / endothelin / cytosolic Ca2+ concentration / PI turnover / mitognesis |
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| Research Abstract |
The transparency of the cornea is very important for the maintenance of good visual function. Normal functional state of corneal epithelial cells as well as endothelial cells are important for the corneal transparency. In this study we have investigated endothelin-induced mitogenesis and the second messenger systems working in cultured rabbit corneal epithelial cells.
We have clearly demonstrated the following :
1) Cultured rabbit corneal endothelial cells produce endothelin. The occurrence of mRNA for prepro-endothelin was found by reverse transcription initiated polymerase chain reaction. In the culture supernatant of the rabbit corneal epithelial cells, radioreactive endothelin was found.
2) Endothelin dose-dependently increases mitogenesis of cultured rabbit corneal epithelial cells. Endothelin 1 dose-dependently increased (EC50 = 0.3 nM) 3H-thymidine uptake of the cell up to 200% of the control. Endothelin was shown to be a comitogen because coexistence of low concentration of fetal bovine serum increased the mitogenic effect.
3) Endothelin increases intracellular cytosolic Ca^<2+> concentration in the cell. Endothelin, at 100 nM, increased cytosolic free Ca^<2+> concentration by more than 200 nM. This phenomenon was preceded by PI turnover.
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