Effects of environmental temperature on physiological function of the brain of the rats suffered hypoxic-ischemic brain insult during neonatal period.

环境温度对新生期缺氧缺血性脑损伤大鼠脑生理功能的影响

• 批准号: 14570057
• 负责人: HOSONO Takayoshi
• 金额: $ 2.24万
• 依托单位: Osaka Electro-Communication University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570057/
• 关键词: brain damage; newborn; environmental temberature; rat; thermoregulation; optic recording; auditory brainstem response; 脳性脳幹反応; 低酸素

In order to investigate the effect of brain cooling of the neonate suffered hypoxic-ischemic brain-damage, we performed experiments using animal model. Under the inspired anesthesia, we ligated left common carotid artery of the 7-day-old rat neonate, and exposed them to the hypoxic air (oxygen 8%). After the hypoxic exposure, we divided the rat neonates to three groups. The first group (hypothermia group) was kept in a room of low environmental temperature for 24 hr, which led the rats to the hypothermia (30 degree). The second group (normothermia group) was kept in a room of normal temperature for 24 hr, which kept the rat body temperature in normothermia. The third group was a control, which had a sham operation. After rearing for three months, we performed auditory brainstem response (ABR) for three groups. ABR was successfully recorded in all the rats under light anesthesia. The interpeak latency of III and V peaks of the normothermia group was significantly elongated than those of the hypothermia and control group. The ratio of the amplitude of V peak versus I peak of the normothermia group was also significantly small than those of the other groups. The inferior colliculus of the normothermia group was significantly atrophic than those of the other groups by using light microscope and imaging-data processing software. These findings indicate that high environmental temperature for the neonate rats after the hypoxic-ischemic insult caused more damages in rat midbrain function than low environmental temperature does. We also performed preliminary investigation on the function of neuronal circuit using optic recording, and found that optic recording using low perfusion temperature might be a useful investigation tools for the study of damaged brain function of suffered neonate animal models.

为了探讨脑降温对新生儿缺氧缺血性脑损伤的治疗作用，我们采用动物模型进行了实验研究。在吸入麻醉下，结扎7日龄新生大鼠左颈总动脉，暴露于低氧空气（氧含量8%）中。缺氧暴露后，我们将新生大鼠分为三组。第一组（低温组）置于低温环境中24 h，使大鼠处于低温状态（30 ℃）。第二组（常温组）置于常温室中24 h，使大鼠体温保持在常温。第三组为对照组，进行假手术。饲养3个月后，对三组动物进行听性脑干反应（ABR）测试。所有大鼠在浅麻醉下均成功记录到ABR。常温组Ⅲ、Ⅴ峰潜伏期较低温组和对照组明显延长。常温组V峰与I峰振幅之比也明显小于其他各组。光学显微镜及图像数据处理软件显示，常温组下丘萎缩明显。结果表明，高环境温度对缺氧缺血后新生大鼠中脑功能的损害比低环境温度更严重。我们还利用光记录技术对神经元环路的功能进行了初步的研究，发现低温光记录技术可能是研究新生儿脑功能损伤的一种有用的研究工具。

项目成果

Hosono T, Nakano M, Terai R, Yagishita T, Okuno R, Akazawa K, Kanosue K.: "Analysis of signal transmissions from suprachiasmatic nucleus in the rat brain using optic recording."Trans Jpn Soc Med Biol Engng. 41(4). 405-409 (2003)

Hosono T、Nakano M、Terai R、Yagishita T、Okuno R、Akazawa K、Kanosue K.：“使用光学记录分析大鼠大脑视交叉上核的信号传输。”Trans Jpn Soc Med Biol Enngng。

Tomimatsu T, Fukuda H, Endoh M, Mu J, Kanagawa T, Hosono T, et al.: "Long-Term Neuroprotective Effects of Hypothermia on Neonatal Hypoxic-Ischemic Brain Injury in Rats, Assessed by Auditory Brainstem Response"Pediatric Res. 53. 57-61 (2003)

Tomimatsu T、Fukuda H、Endoh M、Mu J、Kanakawa T、Hosono T 等人：“低温对大鼠新生儿缺氧缺血性脑损伤的长期神经保护作用，通过听觉脑干反应进行评估”儿科研究。

Hosono T, Nakano M, Terai R, Yagishita T, Okuno R, Akazawa K, Kanosue K: "Analysis of signal transmissions from suprachiasmatic nucleus in the rat brain using optical recording."Transactions of the Japanese Society for Medical and Biological Engineering..

Hosono T、Nakano M、Terai R、Yagishita T、Okuno R、Akazawa K、Kanosue K：“使用光学记录分析大鼠大脑视交叉上核的信号传输。”日本医学和生物工程学会汇刊。

Fukuda H, Tomimatsu T, Kanagawa T, Mu J, Kohzuki M, Shimoya K, Hosono T, et al.: "Postischemic hyperthermia induced caspase-3 activation in the newborn rat brain after hypoxia-ischemia and exacerbated the brain damage"Biology of the Neonate. 84(2). 164-17

Fukuda H、Tomimatsu T、Kanakawa T、Mu J、Kohzuki M、Shimoya K、Hosono T 等人：“缺氧缺血后，缺血后高热诱导新生大鼠大脑中 caspase-3 活化，并加剧脑损伤”生物学

Tomimatsu T, Fukuda H, Endoh M, Junwu Mu, Kanagawa T, Hosono T, et al.: "Long-term neuroprotective effects of hypothermia on neuronal hypoxic-ischemic brain injury in rats, assessed by auditory brainstem response"Pediatric Research. 53. 57-61 (2003)

Tomimatsu T、Fukuda H、Endoh M、Junwu Mu、Kanakawa T、Hosono T 等人：“低温对大鼠神经元缺氧缺血性脑损伤的长期神经保护作用，通过听觉脑干反应进行评估”儿科研究。