Figure 4.

(A) Western blot of three coronary artery homogenates pooled from IR- (n = 10) and sham- (n = 9) operated rats. Results revealed endothelin ET_B receptor band at approximately 50 kDa. Quantification of ET_B immunoreactivity normalized to GAPDH revealed increased ET_B receptor protein levels in downstream LAD segments after IR. Results are expressed as mean ± SEM of three different homogenates where mean of (ET_B immunoreactivity)/(GAPDH immunoreactivity) from sham LAD downstream was set to 100%. *P < 0.05, comparing LAD downstream IR versus LAD downstream sham; Student's t-test. (B) The fluorescence intensity of each group is given as the percentage fluorescence of IR LAD downstream (n = 5) or IR LAD upstream (n = 3) group compared with the sham LAD downstream (n = 3) groups, where the LAD downstream group was set to 100%, and the mean value for each of the other groups was used for comparison. Confocal images showing representative examples of immunofluorescence staining of rat coronary arteries (n = 3–5) of actin (upper row), ET_B receptor (middle row), and merged pictures that show the location of endothelin ET_B receptors in VSMC (bottom row). **P < 0.01, comparing LAD downstream IR versus LAD downstream sham; Student's t-test.