Fig. 1.

IGF-1 stimulates transient cell proliferation in retinal cell cultures. (A,B) Primary cultures from rat neural retinas were treated with IGF-1 (0.1–100 ng/mL) for 48h, or (C,D) IGF-1 (10 ng/mL) for the indicated time intervals. Plots represent mean (±SEM) [³H]-thymidine uptake expressed as percentage of control group (set on 100%; white bars), with sample size provided within each bar. Data were analyzed by one-way ANOVA followed by Holm-Sidak's test (**p < 0.01, ***p < 0.001). EC₅₀ value was calculated in GraphPad Prism 8 using a nonlinear curve fit ([IGF-1] vs. normalized response - method of least squares with variable slope). (E) Representative images (bright-field) of retinal cells treated with IGF-1 (10 ng/mL) for 24h, 48h or 144h (scale bar = 20 μm).