Differential Effect of Three Macrolide Antibiotics on Cardiac Pathology and Electrophysiology in a Myocardial Infarction Rat Model: Influence on Sodium Nav1.5 Channel Expression

Figures

• 

  Figure 1. Serum cardiac enzyme activities in the rat experiments. (a) LDH activity and (b) CK-MB activity in healthy or MI rats treated with azithromycin (Azith), clarithromycin (Clarith), or erythromycin (Eryth). MI: myocardial infarction, LDH: lactate dehydrogenase, CK-MB: creatinine kinase—myocardial band. Data in each set were presented as mean ± standard deviation, and analyzed separately by one-way ANOVA and Bonferroni’s test. * Different from the vehicle group at p-value less than 0.05. # Different from the azithromycin group of the same experiment at p-value less than 0.05 (n = 4–6).

• 

  Figure 2. Electrocardiograms from rats with isoproterenol hydrochloride treated group. Rats were subjected to ECG recording under ether anesthesia in the Biopac data acquisition mp150 device. The figure represents electrocardiograms for rats with myocardial infarction group showing (a) tachycardia, (b) QT prolongation and depressed ST, (c) ST-segment elevation, (d) ventricular premature beats, (e) abnormal Q wave, and (f) T wave changes.

• 

  Figure 3. Electrocardiograms from healthy or myocardial infarction model rats treated with Azithromycin, Clarithromycin, and Erythromycin. Rats were subjected to ECG recording under ether anesthesia in the Biopac data acquisition mp150 device. The left side images for healthy rats treated with azithromycin, clarithromycin or erythromycin showing ST-segment elevation and QT prolongation. The right side images are ECGs from the myocardial infarction rat model experiment treated with azithromycin, clarithromycin or erythromycin.

• 

  Figure 4. Hematoxylin and eosin staining for cardiac specimens in the two rat experiments. (a) Images for specimens were taken from healthy or MI rats treated with azithromycin (Azith), clarithromycin (Clarith), or erythromycin (Eryth). (b) Histologic scores for healthy rat experiment and (c) Histologic scores for MI rat experiment. MI: myocardial infarction. Data presented as medians, and interquartile ranges for the histologic score in each set, were analyzed separately by Kruskal-Wallis ANOVA and Dunn’s Test. * p-value less than 0.05, ** p-value less than 0.01 different from the vehicle group. # p-value less than 0.05: different from the azithromycin group of the same experiment. Cp-value less than 0.05: different from the MI + Clarith group (n = 4–6).

• 

  Figure 5. Masson’s trichrome staining for cardiac specimens in the two rat experiments. (a) Images for specimens were taken from healthy or MI rats treated with azithromycin (Azith), clarithromycin (Clarith), or erythromycin (Eryth). (b) Fibrosis % for healthy rat experiment and (c) Fibrosis % for MI rat experiment. MI: myocardial infarction. Data are medan ± standard deviation for each set’s histologic score analyzed separately by one-way ANOVA and Bonferroni’s test. * p-value less than 0.05, different from the vehicle group. # p-value less than 0.05: different from the azithromycin group of the same experiment (n = 4–6).

• 

  Figure 6. Survival percent in the two rat experiments. (a) healthy rats, and (b) acute MI rats. Survival % was calculated in normal or MI rats treated with azithromycin (Azith), clarithromycin (Clarith), or erythromycin (Eryth). MI: myocardial infarction. Data in each set were analyzed separately by Chi-square Test. Data are % out of 10 rats. * Different from the vehicle group at p less than 0.05. # Different from the azithromycin (Azith) group of the same experiment at p-value less than 0.05.

• 

  Figure 7. Cardiac SCN5A gene expression analysis in the study rat groups. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was applied as an endogenous control in Real-Time PCR runs for data normalization. Relative quantification of the SCN5A gene expression was done based on the quantitative cycle (Cq) values generated from the PCR with the equation: 2−ΔΔCq where ΔΔCq (delta delta quantitative cycle) = (Cq SCN5A − Cq GAPDH)MI group − (Cq SCN5A − Cq GAPDH)Healthy control [13]. (a). Normal rats were subjected to azithromycin, clarithromycin, and erythromycin (200 mg/kg for each drug) versus normal rats without treatment (healthy control). (b). Rats with induced myocardial infarction (MI) subjected to treatment with the same antibiotics versus the MI control group. The mean value of the controls in each group was set at value 1. * Significantly different from saline group in panel (a) (p-values < 0.001), * Significantly different from MI group in panel (b) (p-values < 0.001).