TGF-β1 (A), TGF-β2 (B) and TGF-β3 (C) protein expression during the estrous cycle as determined by Western blot analysis. Total proteins extracts from rat uteri were collected at each days of the estrous cycle. β-actin blots shown were used as controls to correct for loading in each lane. Blots shown are from one representative experiment. Graphics represent Western blot densitometrical analysis. Data represent the mean ± SEM of four independent experiments (four different rats for each day of the estrous cycle). Columns with different letters are significantly different from each other (P < 0.05).