Ernest J T, Goldstick T K
Invest Ophthalmol Vis Sci. 1984 Oct;25(10):1129-34.
In the first series of experiments, preretinal oxygen tensions were measured using microelectrodes in newborn kittens, at 6 +/- 2 days of age, following their placement in an atmosphere of 80 to 90% oxygen for 5 +/- 1 day. The oxygen exposure caused an obliteration of the normally developing retinal vasculature. Preretinal oxygen tensions in the resultant avascular retina were close to zero while those in the vascular retina were near normal. The avascular retina was a "sink" for ocular oxygen. Oxygen breathing resulted in expected increases in preretinal oxygen tension, but, surprisingly, the preretinal oxygen tension decreased with continued oxygen administration. Because the oxygen tension in the avascular retinal area is determined primarily by the choroidal circulation, we speculated that increased oxygen caused a decreased choroidal blood flow. In the second series of experiments, however, choroidal blood flow was measured in the kittens by applying a temperature probe to the sclera and oxygen breathing did not appear to have an effect. These results did not support the initial speculation. It may be that the decrease in preretinal oxygen tension observed with continued oxygen administration resulted from progressive increase in utilization.
在第一组实验中，对6±2日龄的新生小猫，在将它们置于80%至90%氧气的环境中5±1天后，使用微电极测量视网膜前氧张力。氧气暴露导致正常发育的视网膜血管系统闭塞。在由此产生的无血管视网膜中，视网膜前氧张力接近零，而在有血管视网膜中，氧张力接近正常。无血管视网膜是眼部氧气的“汇”。吸氧导致视网膜前氧张力预期增加，但令人惊讶的是，随着持续给予氧气，视网膜前氧张力降低。由于无血管视网膜区域的氧张力主要由脉络膜循环决定，我们推测氧气增加导致脉络膜血流量减少。然而，在第二组实验中，通过将温度探头应用于小猫的巩膜来测量脉络膜血流量，结果显示吸氧似乎没有影响。这些结果不支持最初的推测。持续给予氧气时观察到的视网膜前氧张力降低可能是由于利用率的逐渐增加。
