Cigarette smoke-induced changes in pulmonary vascular and alveolar morphology and right ventricular systolic pressure (RVSP). (a) Representative hematoxylin and eosin (H&E) staining of small pulmonary vessels (original magnification × 40). (b) Representative Masson's trichrome staining of small pulmonary vessels (original magnification × 40). (c) Emphysema-like lesions in the lung after smoke exposure (H&E staining, original magnification × 20). (d) Medial wall thickness (MWT) of pulmonary arterioles. (e) RVSP in hamsters. Con: control group; CS: cigarette smoke-exposed group. Scale bars = 100 μm. Values are expressed as mean ± SD (n = 6). * P < 0.05, significant difference from the control group.