Figure 6 of
Haque, Mol Vis 2003;
Figure 6. Effect of cell density on the daily rhythm of AANAT activity
Cultures were prepared from embryonic day 6 retinas and seeded into 60 mm cultures dishes at a density of 4.5x106 or 9x106 cells per 60 mm dish. Cells were incubated as described in the legend to Figure 1, except that the medium was replaced with fresh medium on both DIV 4 and DIV 6. Cells were harvested at ZT 10 and ZT 18. N=3-5 per group. Significant diurnal fluctuations of AANAT activity were observed in cells seeded at 9x106 cells/dish (p<0.001), but not at 4.5x106 cells/dish (p=0.155). AANAT activity increased significantly in high-density cell culture from ZT10 to ZT 18 on DIV 6 (*p=0.009), and decreased significantly from ZT 18 on DIV 6 to ZT 10 on DIV 7 (p <0.001). Also, AANAT activity was higher in high-density cultures at ZT 18 on DIV 7 compared to ZT 10 on DIV 7 (**p=0.007) and ZT 10 on DIV 8 (p <0.001).