2004 Fiscal Year Final Research Report Summary
Effects of hypoxia on caspase-3 activity in fetal superior colliculus : in vivo optical imagings
| Project/Area Number |
15591157
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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 |
Embryonic/Neonatal medicine
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| Research Institution | Yamaguchi University |
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Principal Investigator |
SAKATA Yoshiyuki Yamaguchi University, School of Medicine, Assistant Professor, 医学部, 講師 (10034927)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIOKA Takashi Yamaguchi University, School of Medicine, Assistant Professor, 医学部, 講師 (50304473)
ISHIKAWA Akinori Yamaguchi University, School of Medicine, Research Associate, 医学部, 助手 (40363098)
TSUCHIMOCHI Hirotsugu Yamaguchi University, School of Medicine, Research Associate, 医学部, 助手 (60379948)
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| Project Period (FY) |
2003 – 2004
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| Keywords | caspase-3 / hypoxia / fetus / in vivo optical recordings / superior colliculus / caspase-3 inhibitor / cyclosporin-A / SOD |
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| Research Abstract |
We studied effects of hypoxia on caspase-3 activity in the superior colliculus (SC) in a fetal rat(embryonic day 22), which was still connected with the anesthetized dam by the umbilical cord. The fetuse was anestethized by urethane and paralyzed by gallamine triethiodide. Caspase-3 activity was measured by using fluorescent caspase-3 substrate. Hypoxia was induced by occlusion of the umbilical cord for 5-10 min. The occlusion caused a transient rise in caspase-3 activity. At 2 or 3 hrs after the occlusion, caspase-3 activation induced by occlusion became more robust and long-lasting compared to the initial occlusion. After reperfusion of the umbilical cord bessels, caspase-3 activity immediately increased and afterward recovered to the control level. Fetuses showing the recovery of caspase-3 activity were found to be survival from hypoxia. The responses of caspase-3 to hypoxia were markedly suppressed by a caspase-3 inhibitor and cyclosporin-A. Cyclosporin-A is known to inhibit a release of cytochrome-C from mitochondria, which induces apoptosis via caspases. Also, superoxide dismutase (SOD) was no effect on caspase-3 activity. These results suggest that caspase-3 activity in fetal SC neurons changes reversibly following hypoxia, which may be associated with protection from hypoxic insults.
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