Expression of Serpine2 mRNA and protein in the uterus during lactation. (A) Expression of Serpine2 mRNA in the postnatal uterus. Quantitative real-time PCR was conducted to analyze gene expression levels. The relative levels of mRNA were normalized to Hprt mRNA levels. Data are presented as the mean of three individual experiments, and error bars represent the standard deviation (SD). a Significant difference compared to other Serpin mRNA levels (p < 0.001). b Significant difference compared to Plau mRNA levels (p < 0.001). (B) Uterine SERPINE2 expression after birth. Forty-five micrograms of total protein prepared from the homogenates of uterine tissue was analyzed by Western blotting. The arrowhead indicates a possible protein complex of SERPINE2 and a certain protease. Arrows indicate the isoform proteins of SERPINE2. The α-tubulin protein level is shown as the loading control. Pd1, postnatal day 1; Pd2, postnatal day 2; Pd14, postnatal day 14.