Niemeyer G
Doc Ophthalmol. 1975 Nov 21;39(1):53-116. doi: 10.1007/BF00578759.
The data show that the enucleated eye of the cat can be maintained in apparently physiologically functioning condition by appropriate arterial perfusion. Under appropriate conditions, photically evoked electrical mass responses can be recorded from various parts of the isolated, perfused eye for 8 to 10 hours. ERGs as well as responses from axonal bundles of the optic nerve exhibit shapes, amplitudes and time courses comparable to their counterparts in vivo. Homeostasis of the perfusion ensures the stability of these light-evoked electrical responses. Transient changes in biophysical parameters of the perfusate rapidly induce marked, although reversible, changes in the amplitudes of b-waves of the ERGs. Increases or decreases in the flow rate of the perfusate induce parallel increases or decreases in the amplitudes of the b-waves as well as of the optic nerve responses. Similar alterations in the oxygen concentration of the perfusate induce similar and proportional changes in the amplitudes of the b-waves. It is concluded, that low flow rates of hemoglobin-free perfusate induce hypoxia; consequently, acceleration of the flow can compensate for hypoxia in a certain range. Previous studies on the effects of and recovery after transient hypoxia in mammalian retina are in concordance with the present data. Progressive decrease of temperature induces gradual and reversible reductions in the amplitudes of the b-waves and increases their latencies and peak-times. It is suggested, that initial hypothermia, which occurs during the period of cannulation, reduces the deliterious effects of the coincident unavoidable hypoxia on retinal neuronal elements. Since light-evoked electrical responses can be maintained for many hours in these preparations and since movements of cardiovascular and respiratory origin, invariably present to varying extent in the in vivo experiments, are eliminated, this preparation is suitable for intracellular recordings from neuronal elements of the retina. Potentials were recorded from cells in various layers of the retina of the cat; intracellular recordings from horizontal cells (S-potentials) are described in detail. Spectral analysis of S-potentials allowed to distinguish between three types according to their inputs: a mixed, rod-cone type, which was most frequently encountered, a pure cone- and a pure rod-type. Light- and electronmicroscopic investigation of the retina after perfusion revealed that (1) the extent of cellular damage depends on the flow rate of the perfusate; (2) little cellular damage is observed if medium flow rates, which maintain physiologic responsiveness of the isolated eye to light, were applied for two hours; (3) high flow rates applied for two hours, or medium flow rates applied for 7 hours appear to induce cystic changes in the pigment epithelium, but only minor changes in the cells of the inner nuclear layer.
数据表明，通过适当的动脉灌注，猫的去核眼可以维持在明显的生理功能状态。在适当条件下，从分离的灌注眼中的各个部位可记录到光诱发的电群体反应，持续8至10小时。视网膜电图（ERG）以及来自视神经轴突束的反应，其形状、幅度和时间进程与体内的对应反应相似。灌注的内环境稳定确保了这些光诱发电反应的稳定性。灌注液生物物理参数的短暂变化会迅速引起ERG的b波幅度明显但可逆的变化。灌注液流速的增加或减少会导致b波以及视神经反应的幅度平行增加或减少。灌注液中氧浓度的类似变化会引起b波幅度类似且成比例的变化。得出的结论是，无血红蛋白灌注液的低流速会导致缺氧；因此，在一定范围内加快流速可以补偿缺氧。先前关于哺乳动物视网膜短暂缺氧的影响及恢复的研究与当前数据一致。温度的逐渐降低会导致b波幅度逐渐且可逆地减小，并增加其潜伏期和峰值时间。有人提出，插管期间出现的初始低温可降低同时不可避免的缺氧对视网膜神经元成分的有害影响。由于在这些制剂中光诱发的电反应可以维持数小时，并且由于在体内实验中总是不同程度存在的心血管和呼吸源性运动被消除，这种制剂适合于从视网膜神经元成分进行细胞内记录。从猫视网膜各层的细胞记录到了电位；详细描述了从水平细胞记录到的细胞内电位（S电位）。对S电位的频谱分析可以根据其输入区分出三种类型：最常见的混合视杆 - 视锥型、纯视锥型和纯视杆型。灌注后对视网膜进行的光镜和电镜研究表明：（1）细胞损伤的程度取决于灌注液的流速；（2）如果以维持分离眼对光的生理反应性的中等流速灌注两小时，则观察到的细胞损伤很小；（3）两小时的高流速灌注或七小时的中等流速灌注似乎会导致色素上皮出现囊性变化，但对内核层细胞的影响较小。
