Neuronal degradation in mouse retina after a transient ischemia and protective effect of hypothermia.
Temporal profile of neuronal deaths in the mouse retina evoked by a transient retinal ischemia and the protective effect of hypothermia on such deaths were evaluated. A transient ischemic insult was induced in the mouse retina by elevating the intra-ocular pressure. The retina tissue responses after reperfusion were histopathologically detected by monitoring the retinal cell death in the ganglion cell layer and inner nuclear layer, using a sequential TUNEL-staining technique, and by measuring the inner retinal thickness. Elevation of intra-ocular pressure induced a time-related appearance of TUNEL-positive cells in the mouse inner retinas. Peak TUNEL staining occurred 12 h after reperfusion. Lowering mice body temperature to 35 degrees C, 33 degrees C and 29 degrees C during the ischemia period significantly inhibited DNA fragmentation of retinal neurons in a lowering temperature dependent manner. In this experiment, the inner retinal thickness was preserved in 29 degrees C group compared with that in 37 degrees C group. From these results, the 45-min transient ischemia and histopathological examination 12 h later provided a reproducible number of retinal neuronal deaths. Furthermore, hypothermic intervention showed a protective effect to salvage retinal neuronal cells from a transient ischemic insult.
Wang
Xiaodan
X
Department of Pharmacology, Gifu University School of Medicine, Japan.
Niwa
Masayuki
M
Hara
Akira
A
Matsuno
Hiroyuki
H
Kawase
Kazuhide
K
Kozawa
Osamu
O
Mow
Hideki
H
Uematsu
Toshihiko
T
D000818:Animals; D001831:Body Temperature / Q000502:physiology; D002545:Brain Ischemia / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy; D016923:Cell Death / Q000502:physiology; D004195:Disease Models, Animal; D007036:Hypothermia, Induced; D020287:In Situ Nick-End Labeling; D008297:Male; D051379:Mice; D009410:Nerve Degeneration / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D010786:Photoreceptor Cells / Q000473:pathology; D015427:Reperfusion Injury / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy; D012162:Retinal Degeneration / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D012165:Retinal Ganglion Cells / Q000473:pathology; D016896:Treatment Outcome