Research on the Mechanism of Neuroprotection of Mild Hypothermia (35℃)-Combination Therapy with Neuroprotective Agents-

亚低温（35℃）神经保护机制研究-神经保护剂联合治疗-

• 批准号: 14570624
• 负责人: KATAYAMA Yasuo
• 金额: $ 2.24万
• 依托单位: Nippon Medical School
• 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-14570624/
• 关键词: Hypothermia; Rat; Focal Ischemia; Apoptosis; Neuroprotection; Immunocytochemistry; In situ hybridization

The aim of this study is to determine whether neuroprotective agents (a selective thrombin inhibitor, argatroban, or immunosuppressant, FK506), would prevent neuronal cell death and whether extra-mildhypothermia (35℃) would enhance the neuroprotecive effect of a selective thrombin inhibitor following transient focal ischemia in rats. Sprague-Dawley rats were subjected to MCAo using an intraluminal suture technique for 2hrs. The rats were repeifused for 24h and decapitated for infarct and edema analysis. Argatroban-treated animals received a continuous injection of argatroban (3.0mg/kg) for 24 hrs by after the onset of ischemia, while vehide-treated groups received same dose of vehide. FK506-treated animals received a single injection of FK506 (0.3mg/kg) venously at 2 hours after isehemic induction, while vehide-treated groups received same dose of vehide. During ischemia, temporal muscle and rectal temperatures were monitored and maintained at 37℃ in the normothermic animals and at 35℃ … More in the hypothermic animals. Animals were randomly divided into the following four groups (each, n=6): (I) vehicle-treated normothermic group (control) at 37℃ (rectal and temporalis muscle temperatures); (II) argatroban or FK506-treated normothermic group at 37℃; (III) vehicle-treated hypothermic group at 35℃; (IV) argatroban or FK506-treated hypothermic group at 35℃. Temporal muscle and rectal temperatures were maintained during ischemia at 37±0.2℃ (normothermic groups) or 35±0.2℃ (hypothermic groups). Argatroban (162±28mm^3) ameliorated the cortical ischemic damage compared with the control (205±55mm^3) significantly (p<0.05). Moreover, argatroban with mild hypothermia decreased the cortical infarct volume (114±28mm^3) significantly compared with those of groups I and III(170±27mm^3) (p<0.05). Furthermore, argatroban with mild hypothermia also decreased the cortical edema (29±11mm^3) volume significantly compared with those of groups I, II and III (68±23mm^3、52±13mm^3、61±16mm^3) (p<0.05). In the borderzone of cortex and striatum, argatroban reduced expression of the proapoptotic Bax protein, whereas increased upregulation of antiapoptotic protein Bcl. Moreover, TUNEL positive cells in the borderzone were decreased in the groups treated by argatroban Argatroban improved neurological symptoms significantly (p<0.05) and also improved survival rate. The combination of FK506 and mild hypothermia significantly reduced infarct volume (cortex,-61%;striatum,-31%) and edema volume (cortex,-57%;striatum,-41%), while mild hypothermia or FK506 alone failed to improve ischemic brain damage. These results demonstrate that extra-mild hypothermia (35℃) enhances neuroprotective effects of neuroprotective agents (a selective thrombin inhibitor, argatroban or immunosuppressant, FK506), suggesting that this combined therapy, extra-mild hypothermia (35℃) plus neuroprotective agents, may be a new therapeutic strategy for the treatment of acute stroke. Less

本研究的目的是确定神经保护剂（选择性凝血酶抑制剂阿加曲班或免疫抑制剂FK506）是否能防止神经元细胞死亡，以及超轻度低温（35℃）是否会增强选择性凝血酶抑制剂在大鼠短暂局灶性缺血后的神经保护作用。采用腔内缝合技术对Sprague-Dawley大鼠进行MCAo 2h。大鼠重复灌胃24h后斩首进行梗死和水肿分析。阿加曲班治疗组在缺血后连续注射阿加曲班（3.0mg/kg） 24小时，而车皮治疗组给予相同剂量的车皮。FK506处理组在缺血诱导后2小时单次静脉注射FK506 (0.3mg/kg)，而车皮处理组则给予相同剂量的车皮。在缺血时，监测常温动物的颞肌和直肠温度在37℃，低温动物的颞肌和直肠温度在35℃。将动物随机分为4组（每组n=6）：(1) 37℃（直肠和颞肌温度）常温灌胃组（对照组）；（II） 37℃加曲班或fk506常温处理组；（三）35℃载药低温组；（IV）阿加曲班或fk506低温组，35℃。缺血时，颞肌和直肠温度分别维持在37±0.2℃（常温组）和35±0.2℃（低温组）。与对照组（205±55mm^3）相比，阿加曲班（162±28mm^3）显著改善皮质缺血损伤（p<0.05）。阿加曲班与亚低温组相比，脑皮质梗死面积（114±28mm^3）明显减少（170±27mm^3），差异有统计学意义（p<0.05）。阿加曲班与亚亚体温组（68±23mm^3, 52±13mm^3, 61±16mm^3）相比，可显著减少脑皮质水肿（29±11mm^3）体积（p<0.05）。在皮层和纹状体交界区，阿加曲班降低促凋亡蛋白Bax的表达，而增加抗凋亡蛋白Bcl的上调。阿加曲班能显著改善神经系统症状（p<0.05），提高生存率。FK506联合亚低温可显著降低梗死体积（皮质，-61%；纹状体，-31%）和水肿体积（皮质，-57%；纹状体，-41%），而亚低温或FK506单用均不能改善缺血性脑损伤。这些结果表明，超亚低温（35℃）可增强神经保护剂（选择性凝血酶抑制剂、阿加曲班或免疫抑制剂FK506）的神经保护作用，提示超亚低温（35℃）加神经保护剂联合治疗可能是治疗急性脑卒中的一种新的治疗策略。少

项目成果

Nito C, Kamiya T, Ueda M, Arii T, Katayama Y: "Mild Hypothermia Enhances the Neuroprotective Effects of FK506 and Expands its Therapeutic Window Following Transient Focal Isehemia in Rats."Brain Res. (in press). (2004)

Nito C、Kamiya T、Ueda M、Arii T、Katayama Y：“轻度低温可增强 FK506 的神经保护作用，并扩大其在大鼠短暂局灶性缺血后的治疗窗口。”Brain Res。

Nibo C, Kamiya T, Ueda M, Arii T, Katayama Y: "Mild Hypothermia Enhances the Neuroprotective Effects of FK506 and Expands its Therapeutic Window Following Transient Focal Ischemia in Rats"Brain Research. (In press).

Nibo C、Kamiya T、Ueda M、Arii T、Katayama Y：“轻度低温增强 FK506 的神经保护作用，并扩大大鼠短暂局灶性缺血后的治疗窗口”大脑研究。