Akeo K, Curran S A, Dorey C K
Macular Disease Research Center, Eye Research Institute of Retina Foundation, Boston, MA.
Curr Eye Res. 1988 Oct;7(10):961-7. doi: 10.3109/02713688809015141.
Despite knowledge of the toxicity of oxygen to the retina, its effects on the retinal pigment epithelium have not been considered. We examined the effect of 20%, 10% and 5% oxygen on growth and superoxide dismutase (SOD) activity of porcine retinal pigment epithelial cells (RPE). Growth of RPE cells was very significantly lower in 20% oxygen than in either 10% or 5%; optimal growth occurred at 10% oxygen, the concentration most like their environment in vivo. Inclusion of SOD and catalase in the media very significantly stimulated growth in 20% oxygen. The SOD activity of RPE cells was significantly related to ambient oxygen. In first passage (P1) cells, SOD activity was 44% lower on day 7 than on day 1 of culture in 20% oxygen (p less than or equal to 0.05). Transfer of cells growing in 20% oxygen to 5% oxygen arrested the decrease in SOD and resulted in significantly higher SOD levels. In fourth passage (P4) cells grown in 20% oxygen, SOD was 25% and 44% lower than cells in 10% and 5% oxygen, respectively. After one week, SOD levels in the P4 cells were significantly higher than in P1. A statistical model of SOD activity in RPE cells indicated significant negative correlations with both oxygen concentration and the cell number. Growth of RPE cells was significantly influenced by oxygen level, days of culture and passage number, but not SOD activity. We conclude that traditional culture conditions support generation of free radicals in tissue culture media that suppress both growth and superoxide dismutase activity.
尽管人们已经了解氧气对视网膜的毒性，但其对视网膜色素上皮的影响尚未得到关注。我们研究了20%、10%和5%氧气对猪视网膜色素上皮细胞（RPE）生长和超氧化物歧化酶（SOD）活性的影响。RPE细胞在20%氧气中的生长显著低于在10%或5%氧气中的生长；在10%氧气中生长最佳，该浓度最接近其体内环境。培养基中加入SOD和过氧化氢酶可显著促进细胞在20%氧气中的生长。RPE细胞的SOD活性与环境氧气显著相关。在第一代（P1）细胞中，培养第7天时，20%氧气环境下的SOD活性比培养第1天时低44%（p≤0.05）。将在20%氧气中生长的细胞转移到5%氧气中可阻止SOD活性下降，并导致SOD水平显著升高。在20%氧气中生长的第四代（P4）细胞，其SOD活性分别比在10%和5%氧气中的细胞低25%和44%。一周后，P4细胞中的SOD水平显著高于P1细胞。RPE细胞中SOD活性的统计模型表明，其与氧气浓度和细胞数量均呈显著负相关。RPE细胞的生长受到氧气水平、培养天数和传代次数的显著影响，但不受SOD活性影响。我们得出结论，传统培养条件会促使组织培养基中产生自由基，从而抑制细胞生长和超氧化物歧化酶活性。
