Discipline of Physiology and Bosch Institute, School of Medical Sciences, University of Sydney, Sydney, Australia.
Invest Ophthalmol Vis Sci. 2014 Apr 3;55(4):2088-96. doi: 10.1167/iovs.13-13525.
Remote ischemic preconditioning (RIP) has been found to be protective of heart and brain against ischemic injury. We have tested the effects of RIP on retinal function using the electroretinogram.
Ischemia remote from the retina was induced in one hindlimb, using a pressure cuff applied for between 5 and 10 minutes. A temperature probe on the footpad confirmed blockage of the circulation. To test the impact of RIP on retinal function, we recorded the dark-adapted flash electroretinogram (ERG) in four groups (n = 5 per group) of Sprague-Dawley rats (sham, 5-minute, 10-minute, and 2 × 5-minute ischemia). Heart rate, breath rate, and peripheral oxygen saturation were monitored using infrared pulse oximetry.
RIP increased both the a- and b-waves by up to 14%, more markedly after the longer periods (10 minutes or 2 × 5 minutes) of ischemia. The effect was tested up to 30 minutes after ischemia and retested at 1 week and 1 month. RIP did not appear to accelerate the initial stages of recovery from photopigment bleach. Systemic oxygen saturation, heart rate, and respiration did not vary consistently during or after remote ischemia.
The effect of RIP on the ERG is a novel finding. Possible mechanisms of this effect are discussed and related to the idea of neuroprotection and to fundamentals of the electroretinogram.
远程缺血预处理（RIP）已被发现可保护心脏和大脑免受缺血性损伤。我们使用视网膜电图测试了 RIP 对视网膜功能的影响。
使用压力袖带对一只后肢进行视网膜以外的缺血，持续 5 至 10 分钟。足底的温度探头证实了循环受阻。为了测试 RIP 对视网膜功能的影响，我们在四组 Sprague-Dawley 大鼠（假手术、5 分钟、10 分钟和 2×5 分钟缺血）中记录了暗适应闪光视网膜电图（ERG）（每组 5 只）。使用红外脉搏血氧仪监测心率、呼吸频率和外周血氧饱和度。
RIP 使 a-和 b-波增加了多达 14%，在较长时间（10 分钟或 2×5 分钟）的缺血后更为明显。该效果在缺血后 30 分钟内进行了测试，并在 1 周和 1 个月时进行了重新测试。RIP 似乎并没有加速光色素漂白的初始恢复阶段。在远程缺血期间或之后，全身氧饱和度、心率和呼吸没有一致变化。
RIP 对 ERG 的影响是一个新发现。该效果的可能机制被讨论，并与神经保护的想法以及视网膜电图的基本原理相关。
