1999 Fiscal Year Final Research Report Summary
Significance of chromium in the ocular tissue
| Project/Area Number |
09671805
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ophthalmology
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| Research Institution | Nagasaki University |
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Principal Investigator |
AMEMIYA Tsugio Medical School, Nagasaki University, Professor, 医学部, 教授 (60026862)
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| Co-Investigator(Kenkyū-buntansha) |
BHUTTO Imran ahmed Medical School, Nagasaki University, Assistant, 医学部, 助手 (20284680)
KITAOKA Takashi Medical School, Nagasaki University, Assistant Professor, 医学部, 助教授 (80234235)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Chromium / retina / diabetes mellitus / rat / trace element / electron microscope |
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| Research Abstract |
Chromium-deficient diet was made by ourselves. Wistar Kyoto rats were fed this diet 20 days after birth. After fed on the deficient diet for 5 or 6 months, blood sugar level became high: it suggests a tendency of diabetes mellitus. Every one hour after light on in the room eyes were enucleated and the retina was fixed in 4% glutaraldehyde and 1% osmic acid to observe with an electron microscope. The laboratory room was kept in 12 hour light and 12 hour dark cycle.
Electron microscopic findings: No abnormal ultrastructural findings were found in each retinal cell at any hour after light on. However, the retinal pigment epithelial cells showed many lamellar structures at any enucleation hours. Although the number of lamellar structures in the normal rat was maximal at 2 hours after light on, then decreased until 4 hours and almost reached to zero after this, the retinal pigment epithelial cells of Cr-deficient rats had maximal number of lamellar structures at 2 hours after light on, but rather many were still kept after 4 hours. These lamellar structures were phagocytized discs of the photoreceptor outer segment. Thus chromium deficiency might induce abnormal function for digestion and breakdown of phagocytized outer segment discs in the retinal pigment epithelium or chromium might induce abnormal circadian rhythm. Therefore, it is considered that chromium is related to the phogocytotic function of the pigment epithelial cells.
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