Table 1.

Outgrowth Area before and after Removal of an Inhibitor

	LY294002 (50 μM)	SR13668 (50 μM)	U0126 (10 μM)
Outgrowth area (mm2) with inhibitor present (at day 17)	0	0	16 ± 1.8
Outgrowth area (mm2) after inhibitor removal (at day 25 or 30)	330 ± 23.9 (day 30)	336 ± 16.1 (day 30)	344 ± 34.4 (day 25)

Human limbal explants on AM inserts were cultured for 17 days in the present of 50 μM LY294002, 50 μM SR13668, or 10 μM U0126. At day 17, explants treated with LY294002 or SR13668 did not show any outgrowth, whereas those treated with U0126 outgrew very little. From this day on, the SHEM medium with the inhibitor was replaced with the fresh medium without the inhibitor. As a result, all explants resumed outgrowth 2 days later, but the outgrowth rate was slower than the control (see Figure 1). Explants previously treated with LY294002 or SR13668 reached 80% confluence by day 30 after the inhibitor was removed, whereas explants previously treated with U0126 reached the similar confluence by day 25.