Western blot of protein isolated from the temporomandibular joint (TMJ) of ovariectomized female rats treated with 17 β-estradiol. Ovariectomized (OVX) rats were given a physiological dose of (E2) or vehicle (No E2) using osmotic pumps and after 7 days of estrogen treatment the TMJ was injected with 30 μl of saline or 30 μg CFA. Protein from the TMJ anterior, disc, retrodiscal and synovial tissues was isolated, 10 μg of protein was loaded in each lane of the gel and the western blot was probed with anti-ERα and then anti-β-actin. (A) Optical densities of the ERα specific band (65 kDa) were determined from the western blot and the optical density of the ERα specific band was normalized to the β-actin band. The normalized mean ± SEM optical density values are shown in the histogram. Each lane in panels B and C is a representative sample from one animal in each treatment group. ** = p < 0.01.