Bill A, Sperber G O
Department of Physiology and Medical Biophysics, University of Uppsala, Sweden.
Graefes Arch Clin Exp Ophthalmol. 1990;228(2):124-7. doi: 10.1007/BF00935720.
Studies on retinal oxygen and glucose consumption in cats and pigs are reviewed and recent experiments with the deoxyglucose method in monkeys are described. In all three species, the retina is supplied with nutrients by both the retinal and the choroidal blood vessels. Studies on regional blood flow and differences in arteriovenous concentration in cats have indicated that under conditions of general anesthesia and exposure to laboratory light, the oxygen supply from the choroid is about 5.6 microliters/min and that from the retinal vessels, 1.3 microliters/min. In pigs the corresponding figures were about 4 and 2.9 microliters/min, respectively. Moderate reductions in perfusion pressure caused by increments in intraocular pressure or reductions in arterial blood pressure resulted in little change in oxygen tension in the inner retina, due to efficient autoregulation of retinal blood flow. Reduced choroidal blood flow was to a large extent compensated by increased differences in arteriovenous concentration. Studies using the deoxyglucose method in monkeys indicated that pentobarbital anesthesia and constant illumination tend to reduce the metabolism of the retina. In darkness, glucose consumption in the photoreceptors was higher than that recorded under conditions of constant illumination with white light. Flickering light at 4 Hz enhanced glucose consumption in the inner retina. At very high intraocular pressures glucose consumption in the retina was enhanced, probably as a result of partial ischemia, with a shift to more anaerobic glucose metabolism.
本文回顾了对猫和猪视网膜氧消耗及葡萄糖消耗的研究，并描述了近期在猴子身上用脱氧葡萄糖法进行的实验。在这三种物种中，视网膜均由视网膜血管和脉络膜血管供应营养。对猫的局部血流及动静脉浓度差异的研究表明，在全身麻醉和实验室光照条件下，脉络膜的氧供应量约为5.6微升/分钟，视网膜血管的氧供应量为1.3微升/分钟。在猪中，相应的数值分别约为4微升/分钟和2.9微升/分钟。眼内压升高或动脉血压降低引起的灌注压适度降低，由于视网膜血流的有效自动调节，导致视网膜内层的氧张力变化不大。脉络膜血流减少在很大程度上通过动静脉浓度差异的增加得到补偿。在猴子身上使用脱氧葡萄糖法的研究表明，戊巴比妥麻醉和持续光照往往会降低视网膜的代谢。在黑暗中，光感受器的葡萄糖消耗量高于在白光持续光照条件下记录到的消耗量。4赫兹的闪烁光增强了视网膜内层的葡萄糖消耗。在非常高的眼内压下，视网膜的葡萄糖消耗增加，这可能是部分缺血的结果，伴随着向更多无氧葡萄糖代谢的转变。
