| Project/Area Number |
11671476
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Anesthesiology/Resuscitation studies
|
|---|
| Research Institution | Akita University |
|---|
Principal Investigator |
NISHIKAWA Toshiaki Akita University, School of Medicine, Professor, 医学部, 教授 (50156048)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KIMURA Tetsu Akita University, School of Medicine, Research Associate, 医学部, 助手 (00312702)
田中 誠 秋田大学, 医学部, 助教授 (50236634)
長崎 剛 秋田大学, 医学部, 助手 (60292380)
合谷木 徹 秋田大学, 医学部, 助手 (30302277)
|
|---|
| Project Period (FY) |
1999 – 2001
|
| Project Status |
Completed (Fiscal Year 2001)
|
| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥200,000 (Direct Cost: ¥200,000)
|
|---|
| Keywords | forebrain ischemia / alpha-2 agonist / dexmedetomidine / hypothermia / glutamate / noreoinephrine / hippocamoal CA1 / stnatum / デキサメデトミジン / 脳保護 / 低体温療法 |
|---|
| Research Abstract |
We examined the effects of dexmedetomidine and mild hypothermia on cerebral injury after transient forebrain ischemia in rats.
Methods: Male Sprague-Dawley rats were anesthetized with halothane, and catheters were inserted into the right internal jugular vein and the tail artery. Rats were assigned to one of four groups; Control (C) group (temporal muscle temperature 37.5℃ and normal saline 0.01 ml/kg), Dexmedetomidine (D) group (37.5℃ and dexmedetomidine 3 μg/kg), Hypothermia (H) group (35.0℃ and normal saline 0.01 ml/kg), Dexmedetomidine and Hypothermia (DH) group (35.0℃ and dexmedetomidine 3 μg/kg). After obtaining predetermined temporal muscle temperature, either dexmedetomidine or normal saline was injected subcutaneously 30 min before start of forebrain ischemia. Transient forebrain ischemia was induced by hemorrhagic hypotension (systolic blood pressure between 45-50 mmHg) and bilateral carotid artery occlusion for 10 min.
Results: Neurological deficit scores (0 point: best, 100 point: worst) on the 7 th day after forebrain ischemia were significantly different among the groups (C: 10 points, D: 14 points, H: 0 points, DH: 5 points, values are median). The number of intact neurons in hippocampal CA1 area in the H group was significantly greater than that in the C group. The area under the glutamate concentration curve during forebrain ischemia in CA1 area in the H group was significantly less than that in the DH group. The increase of norepinephrine concentration in striatum during forebrain ischemia in the H group was significantly less than those in the C, D, and DH groups.
Conclusion: Our results suggest that dexmedetomidine attenuates the neuroprotective effect of mild hypothermia. These results may be due to the inhibitory effects of dexmedetomidine on hypothermia-induced suppression of glutamate and norepinephrine release during forebrain ischemia.
|
