1996 Fiscal Year Final Research Report Summary
Electrophysiological Study on the Effect of Nitric Oxide on Ischemic Retina
| Project/Area Number |
07671902
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Ophthalmology
|
|---|
| Research Institution | Chiba University |
|---|
Principal Investigator |
TSUYAM Yoshihiko Chiba University, School of Medicine, Assistant, 医学部, 助手 (50210571)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MIZOTA Atsushi Chiba University, School of Medicine, Assistant, 医学部, 助手 (10239262)
|
|---|
| Project Period (FY) |
1995 – 1996
|
| Keywords | Nitric oxide / Ischemic retina / Electroretinogram / L-arginine / Nitro-L-arginine methyl ester hydrochloride / Sodium nitroprusside |
|---|
| Research Abstract |
Nitric oxide (NO) has a characteristics of free radical and was regarded as noxious to organisms. But recent researches show that NO is an important substance for transcellular signal transduction. It also seems to act as neurotransmitter in the nervous system. In ischemic nerve tissue a release of glutamate is one of critical factors that increase neuronal death and some experiments suggest that NO may be involved in this process. Here we provide evidence that NO leads to neuroprotection in ischemic retina in vivo. White rabits' eyes were subjected to 60 minutes of ischemia by raising intraocular pressure. Before ischemia the eyes were pre-treated intravitreously with each of NO-precursor L-arginine (L-Arg), NO synthase-inhibitor nitro-L-arginine methyl ester hydrochloride (L-NAME), No-donor sodium nitroprusside (SNP) and only solvent. The amplitude of be wave were measured and the recovery ratio of b-wave were analyzed every hour after reperfusion. The recovery ratio of b-wave in the eyes with L-Arg and with SNP increased more rapidly than that of the control, while the recovery ratio in the eyes with L-NAME increased in a similar way to that of the control. These results suggest NO plays a neuroprotective role in ischemic retina. It may be involved with S-nitrosylation of some proteins, including one of glutamate receptors, N-methyl-D-aspertate (NMDA) receptors.
|
