Figure 3. Changes in glutathione level during lens culture. Bovine lenses were incubated in a final volume of 40 ml in a GSH/Gly-Gly medium (see Methods) alone (circles), or in the presence of 10 mM serine/borate (squares) or 10 mM serine/borate and 0.5 mM Cys-Gly (triangles). Closed and open symbols refer to the extra-lenticular level of total glutathione and GSSG, respectively. Inset: bars refer to total glutathione intra-lenticular level measured after 24 h of incubation in the following conditions: a: standard medium; b: GSH/Gly-Gly medium; c: GSH/Gly-Gly/SB medium; d: GSH/Gly-Gly/SB medium supplemented with Cys-Gly. Statistical analysis was performed comparing the values measured under different conditions at the same time of incubation. (#): p<0.05 versus GSH/Gly-Gly medium, (###): p<0.001 versus GSH/Gly-Gly medium, (*): p<0.05 versus GSH/Gly-Gly medium supplemented with Cys-Gly, and (***):<0.001 versus GSH/Gly-Gly medium supplemented with Cys-Gly. Values are reported as the mean of at least five different experiments; the error bars represent the standard error of the mean.