1997 Fiscal Year Final Research Report Summary
The neurotrophic factor in retinal degeneration of the rat
Project/Area Number |
08672026
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Ophthalmology
|
Research Institution | Kagoshima University |
Principal Investigator |
UNOKI Kazuhiko Kagoshima University, University Hospital, Assistant Prorfessor, 医学部・附属病院, 講師 (60193926)
|
Project Period (FY) |
1996 – 1997
|
Keywords | rat / midkine / ischemia / light damage / rescue / retinal degeneration |
Research Abstract |
We evaluated the protective effect of midkine (MK), the product of a retinoic acid responsive gene, on ischemia-reperfusion injured retinal degeneration in the rats. MK or buffer controls were injected intravitreally two days before ischemia reperfusion injury. After 7 or 14 days of ischemic damage, the eyes were perfused with a fixative, bisected along the vertical meridian, embedded in plastic and then sectioned. The degree of retinal ischemic damage was assessed for plastic-embedded sections by cytological analysis, measuring the thickness of several layrs and by counting the numbers of the ganglion cells. Seven and 14 days after ischemia-reperfusion injury, the retinas of uninjected controls and those of rats injected with phosphate buffered saline (PBS) showed a decrease in the thickness and a reduction in the cell numbers in inner retinal layrs. The photoreceptor layr and outer nuclear layr appeared almost normal. The retinas of MK-injected eyes were found to be transiently rescued or protected from ischemic damage. It was very hard to get such amount of MK from L-cell system, therefore Kaneda et al. produced a recombinant basulovirus clone which expresses a large amount of mouse MK in the culture medium than L-cell. We evaluated the survival promoting activity of each midkine produced by L-cell system, baculo virus system in the constant light-induced photoreceptor degeneration of the rat. Also, Rat pleiotrophin (PTN,known as heparin-binding growth-associated molecule) was examined in light damaged model of the rat. MK from L-cell appeared a little higher score than MK from baculovirus The eyes injected with PTN had a low score.
|