Changes in the remodeling of pulmonary arterioles and RVSP after chymase inhibition with chymostatin. (a) Representative van Gieson's elastic staining of small pulmonary vessels (original magnification × 40). Scale bars = 100 μm. Con: control; CS: cigarette smoke exposure; Chy: treatment with 2 mg/kg chymostatin alone; CS+Chy: treatment with smoke exposure plus 2 mg/kg chymostatin. (b) MWT of pulmonary arterioles. (c) RVSP. Control: control group; CS: cigarette smoke-exposed group; Chymo: chymostatin treatment. Values are expressed as mean ± SD (n = 6). * P < 0.05, significant difference from the control group. # P < 0.05, significant difference from the smoke-exposed group.