Fig. 6.

Response of granulosa cells (GCs) to high and low oxygen tensions. On day 2, GCs of young and aged cows with 70–80% confluence were cultured under conditions of 5% (low) or 20% (high) O₂ for 24 h, and then GCs or spent culture medium were used for the experiments. (a) Survival rate of GCs, (b) Mt-number in GCs, (c) ATP (pM) content in 20,000 GCs, (d) Glucose consumption (μM/20,000 GCs), and (e) mitochondrial DNA content in spent culture medium. The cell-free Mt-number (Cf-mtDNA copy number) was normalized to the GC number in a well: 20,000 GCs were cultured in 100 μl of medium. (a–d) Different superscripts indicate significant differences (P < 0.05).