Figure 6. SMMHC isoform protein expression in rabbit bladder smooth muscle. (Panel A) SDS-PAGE analysis of total protein extracts from urinary bladder smooth muscle, using a 4.5% highly porous SDS polyacrylamide gel. Lanes 1 to 3 correspond to normal female rabbit, Ovx, and Ovx estrogen-treated (ET), respectively. SM1 and SM2 were separated electrophoretically and visualized by Coomassie brilliant blue staining. (Panel B) Western blot analysis of smooth muscle myosin SM1/SM2 by using an antibody against SMMHC. (Panels C and D) Level of MHC protein expression and SM2-to-SM1 ratios as determined by densitometric scanning of the gel in Panel A in control (N), Ovx, and Ovx-ET rabbits, respectively. Relative SM2-to-SM1 protein ratios in the 3 groups (N: 2.8:1, Ovx: 3.38:1, and Ovx-ET: 1.66:1) differed significantly (P < .05). Reproduced with permission from Sanchez-Ortiz et al, 2001.