Voss Logan J, Whittle Nicola, Lamber Oliver, Envall Gustav, Sleigh Jamie
Anaesthesia Department, Waikato District Health Board, Hamilton, New Zealand.
School of Science and Engineering, University of Waikato, Hamilton, New Zealand.
IBRO Rep. 2020 Nov 4;9:302-309. doi: 10.1016/j.ibror.2020.10.007. eCollection 2020 Dec.
Hypoxic-ischaemic brain injury is a major cause of morbidity and mortality internationally. Using an in vitro isolated cortex model, this study investigated the optimal cerebrospinal fluid oxygenation parameters for rescuing metabolically challenged cortical tissue. In particular, we asked whether maximizing oxygen content with oxygen nanobubbles could support improved tissue recovery. Mouse cortical slices were metabolically starved, followed by recovery in artificial cerebrospinal fluid (aCSF) containing different levels of dissolved oxygen ranging from mean(SD) 2(0.5) to 39(1.0) mg/L; with and without oxygen nanobubbles. Tissue recovery was assessed by quantifying and comparing the amplitude, length, high frequency content and event frequency of seizure-like events generated in no-magnesium aCSF at the beginning and end of the protocol. In general, there was improved recovery with increasing oxygen content up to 25-34 mg/L. The outcome of slices recovered in nanobubbled aCSF was no different to conventionally oxygenated slices with similar dissolved oxygen content. Dissolved oxygen content above 34 mg/L afforded no additional benefit. In conclusion, aCSF dissolved oxygen content of approximately 30 mg/L is optimal for cortical tissue recovery from metabolic starvation, which is easily achievable using conventional oxygenation methods. Oxygen in the form of nanobubbles does not appear to be readily available for tissue oxidative processes in this model.
缺氧缺血性脑损伤是全球发病和死亡的主要原因。本研究使用体外分离皮质模型,探究了挽救代谢受损皮质组织的最佳脑脊液氧合参数。具体而言,我们研究了用纳米氧泡使氧含量最大化是否有助于改善组织恢复。对小鼠皮质切片进行代谢饥饿处理,然后在含有不同溶解氧水平(平均(标准差)2(0.5)至39(1.0)mg/L)的人工脑脊液(aCSF)中恢复,分为添加和不添加纳米氧泡两组。通过量化和比较实验开始和结束时在无镁aCSF中产生的癫痫样事件的幅度、长度、高频含量和事件频率,评估组织恢复情况。一般来说,溶解氧含量增加至25 - 34mg/L时,恢复情况有所改善。在含纳米氧泡的aCSF中恢复的切片结果与溶解氧含量相似的传统氧合切片并无差异。溶解氧含量高于34mg/L并无额外益处。总之,对于从代谢饥饿中恢复的皮质组织,aCSF溶解氧含量约30mg/L最为适宜,这使用传统氧合方法很容易实现。在该模型中,纳米氧泡形式的氧似乎不易用于组织氧化过程。