Representative immunohistochemistry localizing BKCa subunits in intramyometrial arteries and myometrial smooth muscle from a nonpregnant woman. Tissue is paired with the uterine artery in Figure 2. Panels A, C, E and G are at 20X magnification; panels B, D, F and H are at 40X. Panels A and B are controls with nonimmune serum, C and D are the pore α-subunit, E and F the β1-subunit, and G and H the β2-subunit. Intramyometrial arteries are denoted by the arrows and myometrial smooth muscle by m.