Insulin inhibits RDH10 and DHRS3 transcription. Cells were continued in growth medium or transitioned to serum-free medium. Additions of hormones, glucose, or inhibitors were made at the time of the transition to serum-free medium. A, HepG2 cells were transitioned from serum-containing (growth) to serum-free (SF) medium at 0 h and mRNA of RDH10 and glucose-6-phosphatase (G6PC) were measured. B, cells were maintained in growth medium or transitioned to serum-free medium and treated 4 h ± 10 nm insulin. C, cells were maintained in growth medium or transitioned to serum-free medium and treated 6 h with 10 nm insulin, or 3 or 20 mm glucose, or 100 nm glucagon. D, cells were maintained in growth or transitioned to serum-free medium and treated 4 h with 10 nm insulin, ± 25 μg/ml of ActD, or ± 10 μg/ml of CHX: *, p < 0.05; **, p < 0.005; ***, p < 0.0005 relative to growth values; ##, p < 0.005; ###, p < 0.001 relative to serum-free values; &&, p < 0.005. ns, not significantly different from growth medium.