Linsenmeier R A, Yancey C M
Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208.
Invest Ophthalmol Vis Sci. 1989 Apr;30(4):612-8.
Double-barreled oxygen microelectrodes were used to measure the distribution of oxygen within the dark adapted cat retina during systemic hyperoxia (100% O2 inspired). Oxygen tension (PO2) decreased monotonically from the choroid to the vitreous humor in most cases, showing that a greater portion of the retina was supplied by the choroid during hyperoxia than during normoxia. In the proximal half of the retina the PO2 increased during hyperoxia by an average of about 40 mm Hg, while the increase in the distal retina was larger. At the choroid the average increase in PO2 was about 150 mm Hg. Analysis of the oxygen profiles showed that photoreceptor oxygen consumption was unchanged during hyperoxia. Retinal PO2 increased rapidly at the beginning of hyperoxia, and often partially recovered from its peak value during hyperoxia, even in the distal retina, suggesting that the choroidal circulation may have some limited autoregulatory capacity. As in normoxia, retinal illumination led to an increase in PO2 in the distal retina, due to a decrease in oxygen consumption. The light-evoked increase in PO2 was larger during hyperoxia, but the underlying change in oxygen consumption was probably the same as in normoxia.
使用双管氧微电极测量在全身高氧（吸入100% O₂）期间暗适应猫视网膜内的氧分布。在大多数情况下，氧张力（PO₂）从脉络膜到玻璃体呈单调下降，表明在高氧期间视网膜由脉络膜供应的部分比在常氧期间更大。在视网膜近端一半区域，高氧期间PO₂平均增加约40 mmHg，而远端视网膜的增加更大。在脉络膜处，PO₂的平均增加约为150 mmHg。对氧分布曲线的分析表明，高氧期间光感受器的氧消耗没有变化。高氧开始时视网膜PO₂迅速增加，并且即使在远端视网膜，在高氧期间也常常从峰值部分恢复，这表明脉络膜循环可能具有一定的有限的自身调节能力。与常氧时一样，视网膜光照导致远端视网膜PO₂增加，这是由于氧消耗减少。高氧期间光诱发的PO₂增加更大，但氧消耗的潜在变化可能与常氧时相同。
