Chen E, Pallon J, Forslind B
Research Department, St. Erik's Eye Hospital, Stockholm, Sweden.
Graefes Arch Clin Exp Ophthalmol. 1995 Mar;233(3):163-7. doi: 10.1007/BF00166609.
Blue-light exposure inhibits cytochrome oxidase and may therefore inhibit retinal metabolism. The reduced metabolism decreases the extrusion of calcium from the photoreceptor cell. Overload of calcium is proposed as one of the factors that lead to photoreceptor degeneration after light exposure. The light-induced photoreceptor degeneration can be ameliorated by calcium overload blocker. In the present study the calcium concentration was measured in the inner and outer segment layer of the rat retina.
Six eyes were exposed to blue (404 nm) light at a retinal dose of 380 kJ/m2. Five eyes served as the control group. The calcium and sulphur distributions were measured with a nuclear microprobe in the freeze-dried rat retina. The proton beam size was 12 x 12 microns and the energy of the protons was 2.55 MeV. The calcium concentration was calculated using sulphur as a reference.
The level of calcium per milligram sulphur was 21 micrograms (range 17-23 micrograms) in the inner segment of the control retina. It increased to 62 micrograms/mg sulphur (range 57-67 micrograms) and 61 micrograms/mg sulphur (range 58-66 micrograms) 1 h and 12 h after blue-light exposure, respectively.
The findings of the present study support the idea that accumulation of calcium in the inner segment layer is one of the factors that cause photoreceptor degeneration.
蓝光照射会抑制细胞色素氧化酶，因此可能会抑制视网膜代谢。代谢降低会减少光感受器细胞中钙的排出。钙超载被认为是光照后导致光感受器变性的因素之一。钙超载阻滞剂可改善光诱导的光感受器变性。在本研究中，测量了大鼠视网膜内段和外段层的钙浓度。
六只眼睛以380 kJ/m²的视网膜剂量暴露于蓝光（404 nm）下。五只眼睛作为对照组。用核微探针测量冷冻干燥大鼠视网膜中的钙和硫分布。质子束大小为12×12微米，质子能量为2.55 MeV。以硫为参考计算钙浓度。
对照视网膜内段每毫克硫的钙水平为21微克（范围17 - 23微克）。蓝光照射后1小时和12小时，分别增加到62微克/毫克硫（范围57 - 67微克）和61微克/毫克硫（范围58 - 66微克）。
本研究结果支持以下观点，即内段层中钙的积累是导致光感受器变性的因素之一。
