(a) Immunohistochemistry of claudin-1 in vaginal tissue from animals of the control (Con), ovariectomy (Ovx), and ovariectomy plus 17β-estradiol treatment (Ovx + Est) groups. Claudin-1 was most intense in the superficial layer of the vaginal epithelium. (b) Immunoblotting of claudin-1 in the rat vagina. The lower panels denote the means ± standard error of 6 experiments for each condition determined by densitometry relative to beta-actin. ∗P < 0.05 versus control. ∗∗P < 0.05 versus Ovx.