Department of Forensic Medicine.
Department of Premedical Program, School of Medicine, Chosun University, Gwangju 61452, South Korea.
Int J Med Sci. 2018 Apr 27;15(7):696-702. doi: 10.7150/ijms.24257. eCollection 2018.
Evans blue dye (EBD) is the most common indicator to analyze the extent of blood-brain barrier (BBB) breakdown in several neurological disease models. However, the high-dose of EBD (51.9 mg/kg) is usually required for visualization of blue color by the human eye that brings potential safety issues. To solve this problem, low-dose of EBD was applied for the near-infrared (NIR) fluorescence-assisted quantitation of BBB breakdown in photothrombotic stoke model. Animals were allocated to seven dose groups ranging from 1.35 nmol (5.19 μg/kg) to 13.5 μmol (51.9 mg/kg) EBD. EBD was undetectable in the non-ischemic brain tissue, and the fluorescence signals in the infarcted hemisphere seemed proportional to the injected dose in the dose range. Although the maximum fluorescence signals in brain tissue were obtained with the injections of 1.35 nmol ~ 13.5 μmol EBD, the background signals in the neighboring brain tissues were significantly increased as well. Since the high concentration of EBD is necessary for color-based identification of the infarcted lesion in brain tissues, even 10-fold diluted could not be distinguished visually by naked eye. NIR fluorescence-assisted method could potentially provide new opportunities to study BBB leakage just using small amount of EBD in different pathological conditions and to test the efficacy of various therapeutic strategies to protect the BBB.
伊文思蓝染料（EBD）是分析几种神经疾病模型中血脑屏障（BBB）破裂程度的最常用指示剂。然而，为了用肉眼观察到蓝色，通常需要使用 EBD 的高剂量（51.9mg/kg），这带来了潜在的安全问题。为了解决这个问题，在光血栓性中风模型中，使用低剂量的 EBD 进行近红外（NIR）荧光辅助定量 BBB 破裂。动物被分为七个剂量组，EBD 剂量范围从 1.35nmol（5.19μg/kg）到 13.5μmol（51.9mg/kg）。非缺血性脑组织中无法检测到 EBD，并且梗塞侧半球的荧光信号似乎与注射剂量在剂量范围内呈比例关系。尽管在注射 1.35nmol 到 13.5μmol EBD 时，脑组织中获得了最大的荧光信号，但邻近脑组织中的背景信号也显著增加。由于高浓度的 EBD 对于基于颜色的脑组织梗塞病变的识别是必要的，即使是 10 倍稀释也无法用肉眼区分。NIR 荧光辅助方法有可能为研究不同病理条件下 BBB 渗漏提供新的机会，仅使用少量的 EBD，并测试各种保护 BBB 的治疗策略的疗效。
