Fig. 4.

Sirius red staining under polarized light demonstrates the antifibrotic effects of doxazosin and carvedilol on carbon tetrachloride (CCl4)-induced fibrosis. (A) Masson trichrome staining revealed an increase in collagen deposition (*) in the portal tract in the 50CCl4 and placebo groups. However, an attenuation of collagen deposition was observed in the 6-hydroxydopamine (6-OHDA), doxazosin and carvedilol groups. (B) A significant reduction in the fibrotic area was observed in doxazosin- and carvedilol-treated animals. (C) The control group showed normal histological architecture with collagen type III. In the liver sections of hamsters treated with 50 mg/kg of CCl4, there were multiple regenerative nodules (*) surrounded by collagen type I. The placebo group had a reduction of collagen deposits (white arrows) with a normal level of collagen type I. The chemical sympathectomy generated incomplete septa of collagen type III (white arrows), forming enlarged regenerative nodules (*). Doxazosin treatment promoted a shift to collagen type III (white arrows); no evidence of regenerative nodules was observed. Carvedilol treatment resulted in little collagen type III (white arrows) and few regenerative nodules (*). Values are represented as the mean±SD. ^†p<0.05 versus control; ^‡p<0.05 versus 50CCl4; ^§p<0.05 versus placebo.