Winkler B S
Exp Eye Res. 1986 Jun;42(6):585-93. doi: 10.1016/0014-4835(86)90048-5.
Using the isolated rat retina, the present experiments have examined the effects of varying the type and concentration of buffer system with and without changes in external pH on lactic acid production and ERG potentials. The buffers chosen for study included bicarbonate/CO2, HEPES, Tris+ and phosphate. High rates of retinal glycolysis were observed with either 25 mM bicarbonate and 5% CO2 (control condition) or with 30 mM quantities of the other buffers at an external pH of 7.4. Significantly lower rates of retinal glycolysis were obtained when the concentration of each buffer was reduced to 10, 5 or 3 mM without a change in external pH. Lactic acid production was also decreased when the external pH was lowered regardless of the buffer system employed. The a- and b-waves were well maintained in the presence of 25 mM bicarbonate and 5% CO2. Lowering the bicarbonate concentration at constant external pH led to a decrease in their amplitudes. With either Hepes, Tris+ or phosphate employed at concentrations between 3 and 30 mM the amplitude of the a-wave was reduced and the b-wave was lost. These results show that the nature and concentration of the buffer system used in in vitro retinal studies influences metabolic and electrical activities in this tissue and emphasize the importance of the buffer as a constituent of the incubation medium.
利用分离的大鼠视网膜，本实验研究了在外部pH不变和改变的情况下，缓冲系统的类型和浓度变化对乳酸生成和视网膜电图（ERG）电位的影响。用于研究的缓冲液包括碳酸氢盐/二氧化碳、羟乙基哌嗪乙磺酸（HEPES）、三羟甲基氨基甲烷（Tris+）和磷酸盐。在外部pH为7.4时，25 mM碳酸氢盐和5%二氧化碳（对照条件）或30 mM的其他缓冲液均可观察到较高的视网膜糖酵解速率。当每种缓冲液的浓度降至10 mM、5 mM或3 mM而外部pH不变时，视网膜糖酵解速率显著降低。无论采用何种缓冲系统，降低外部pH时乳酸生成也会减少。在存在25 mM碳酸氢盐和5%二氧化碳的情况下，a波和b波维持良好。在外部pH恒定的情况下降低碳酸氢盐浓度会导致其振幅降低。当使用浓度在3 mM至30 mM之间的HEPES、Tris+或磷酸盐时，a波的振幅降低，b波消失。这些结果表明，体外视网膜研究中使用的缓冲系统的性质和浓度会影响该组织的代谢和电活动，并强调了缓冲液作为孵育培养基成分的重要性。
