Fig. 1. Effect of TGF-ß1 and EGF on cell proliferation and apoptosis in filter-cultured pig thyroid epithelial cells. (A) [³H]Thymidine incorporation. Confluent cells stimulated with EGF (10 ng/ml) or TGF-ß1 (10 ng/ml) alone or in combination were simultaneously exposed to 1 µCi/ml [³H]thymidine, added to the basal medium of the bicameral chamber, for 0-24 or 24-48 hours, after which incorporated radioactivity was counted. Mean±s.d. (n=3). (B) Caspase-3 activity. Filter cultures were lysed after growth factor stimulation at the indicated times and the degradation rate of a caspase-3 specific fluorogenic substrate (DEVD-AMC) was measured. Mean±s.d. (n=3).