Abstract
Low-energy extracorporeal shock waves (LESW) have been studied as a new treatment for angina pectoris and several ischemic diseases because of its effect on angiogenesis and inhibition of fibrosis of the heart. The effect of LESW on fibrosis in liver cirrhosis has not been studied. The aim of this study was to verify the amelioration of liver fibrosis by LESW and elucidate its mechanisms in a rat model of drug-induced liver cirrhosis. Male Wistar rats aged 7 weeks were injected with carbon tetrachloride intraperitoneally twice a week for 12 weeks. Eight rats underwent LESW therapy (0.25 mJ/mm(2), 4 Hz, 1000 shots) under general anesthesia (shock wave group). Seven rats only underwent general anesthesia (control group). Quantitative analysis showed that the area of fibrosis in the shock wave group was significantly reduced compared with the control group (11,899.9 vs. 23,525.3 pixels per field, p < 0.001). In the shock wave group, the mRNA expression of transforming growth factor (TGF)-β1 was significantly suppressed (0.40-fold, p = 0.018) and vascular endothelial growth factor-B was significantly increased (1.77-fold, p = 0.006) compared with the control group. Serum albumin was significantly higher in the shock wave group than in the control group (3.0 vs. 2.4 g/dl, p = 0.025). Aspartate aminotransferase/alanine aminotransferase ratio decreased by LESW compared with the control group (1.49 vs. 2.04, p = 0.013). These results suggest that LESW therapy ameliorates liver fibrosis by reducing the expression of TGF-β1 and increasing the expression of angiogenic factors, and improves hepatic function.