MMP9 and Myocardial fibrosis: Western blot detection of myocardial fibrosis-related proteins showed that the expressions of α-SMA, Collagen-I, Collagen-III, MMP-2, and MMP-9 in the HG group were significantly up-regulated (P<0.05), and the above protein expressions in HG + SP group were significantly down-regulated (P<0.05) (Figure 5A).