Effect of glucose and oxygen on cytochrome c in rat islets (A and B). The concentration of glucose under normoxic conditions was switched between low and high glucose resulting in a reproducible
increase and return to baseline of absorption due to cytochrome c. Pre-equilibrating the media with 95% oxygen only slightly
decreased the absorption, indicating that islets were adequately oxygenated even when the media was normoxic. When the media
was pre-equilibrated with 0% oxygen, the absorption increased dramatically reflecting the reduction of the cytochrome c. Spectra
were obtained every minute, and the flow rate was 200 μl/min MEM.