Fig. 4.

BrCr treatment inhibits phosphorylation of STAT5 but not ERK1/2. A: lysates were prepared from mammary glands isolated from mice treated with BrCr 0, 4, 8, 16, and 24 h after initial treatment with BrCr. Treatment with BrCr was repeated at 8 and 16 h to maintain low serum levels of PRL. Immunoblots were probed with anti-phospho-STAT5, anti-STAT5, anti-phospho-ERK, anti-ERK, and anti-actin to demonstrate equal phospho-STAT5 and phospho-ERK. Blots show representative data from individual mice. B: graphs show quantitative data from 4 mice per experiment.