Table 1

Cardiac function after coronary microembolization

Figure 1.

Histopathology of post-CME myocardial microinfarcts. HE staining of tissue samples from the coronary microembolization group revealed myocardial microinfarcts with a low level of inflammatory cell infiltration. However, a portion of cardiomyocyte nuclei is not visible. The arrow indicates the presence of a 42 μm microsphere following the experimental protocol (HE staining, original magnification×400).

Figure 2.

Histopathology of myocardial microinfarcts. Hematoxylin basic fuchsin picric acid (HBFP) staining of tissue samples revealed no infarct in the control group. Microinfarcts in the tissue samples from the CME and metoprolol groups are indicated by arrows. Normal myocardial cytoplasm is stained yellow, the nuclei are stained blue, and the ischemic myocardium is stained red (HBFP staining,original magnification×100).

Figure 3.

Photomicrographs showing effect of metoprolol on apoptosis following CME. TUNEL assay revealed the myocardial apoptosis in the control, CME, and metoprolol groups. Normal cell nuclei are stained pale blue while the apoptotic cardiomyocyte nuclei (arrows) are stained brown (original magnification×400).

Figure 4.

Graph showing effect of metoprolol on apoptosis following CME. Myocardial apoptosis after CME (TUNEL assay) was detected primarily in the myocardial microinfarction foci and the peripheral zones. In control animals, myocardial apoptosis was occasionally found in the subendocardium and papillary muscles. The data (n=10) are expressed as means ± SD.Compared with the control group, *P<0.05;compared with the CME group, #P<0.05.

Figure 5.

Effect of metoprolol on caspase-3 expression following CME. A: The relative expression levels of activated caspase-3 protein were determined by using western blot; the IA values were normalized to GAPDH expression levels. Lanes 1, 2, and 3 in the representative gel show caspase-3 expression in the control, CME (after 6 hours), and metoprolol groups, respectively. B: The data obtained (n=10) were expressed and compared between the groups as means ± SD values, herein presented graphically. Compared with the control group, *P<0.05; compared with the CME group, #P<0.05.