Objective: To study the effect of compatibility of Astragali Radix and Salviae Miltiorrhizae Radix et Rhizoma extract on pathological changes of myocardium in rats after myocardial infarction (MI). Method: Left coronary artery of Sprague-Dawley rats were ligated to make MI models. The rats were randomly subjected to MI model group

astragalus group

Salviae Miltiorrhizae Radix et Rhizoma group

compatibility of Astragali Radix and Salviae Miltiorrhizae Radix et Rhizoma and sham-operated group

each group consisted of 8 rats. All the treatment groups were orally given 20 mg·kg-1 ·d-1 drug extract

and the MI group and sham-operated group were fed 0.9% sodium chloride 20 mL·kg-1 ·d-1. 8 weeks later

the rats were sacrificed

the hemodynamic changes in rats were determined

and the segmental heart samples were collected for hematoxylin and eosin staining

masson staining and histological evaluation on expression of protein kinase D1(PKD1). Result: Compared with the MI group

the left ventricular systolic pressure(LVSP) and maximal decrease and increase rate of pressure in left ventricle of Astragali Radix group

Salviae Miltiorrhizae Radix et Rhizoma group

compatibility of Astragali Radix and Salviae Miltiorrhizae Radix et Rhizoma or sham-operated group increased significantly (P<0.01)

while the left ventricular end diastolic pressure(LVEDP) decreased significantly (P<0.01). There were serious myocardial necrosis

increased fibroblasts

accompanied by inflammatory cell infiltration in the rat of MI group

and slightly fuzzy cell morphology

nuclear hypertrophy

mild proliferation of fibroblasts

inflammatory cells decreasing in the Astragali Radix or Salviae Miltiorrhizae Radix et Rhizoma group

while clearer cell morphology

rare fibroblasts and inflammatory cells in the compatibility of Astragali Radix and Salviae Miltiorrhizae Radix et Rhizoma group

according to the HE staining analysis. The masson staining results showed that the MI group consisted of more myocardial collagen tissue

yet each treatment group consist of mainly red myocardial tissue

intermingled collagen tissue. The PKD1 protein expression in the cytoplasm of myocardial tissue of the MI group increased significantly (P<0.01)

compared to all the treatment group

despite of decreasing obviously

but still visible in the Astragali Radix or Salviae Miltiorrhizae Radix et Rhizoma group. And the PKD1 protein expression in the compatibility of Astragali Radix and Salviae Miltiorrhizae Radix et Rhizoma group declined significantly compared to the Astragali Radix or Salviae Miltiorrhizae Radix et Rhizoma group(P<0.05). Conclusion: Our study reveals that the compatibility of Astragali Radix and Salviae Miltiorrhizae Radix et Rhizoma can significantly ameliorate the abnormal hemorheological indicators and pathologic lesions after myocardial infarction

which may be related to the expression regulation of PKD1 protein in myocardial tissue.