Abstract Objective To investigate the effects of atorvastatin calcium on pulmonary vascular remodeling, the authors explored the regulatory mechanism of Histone Deacetylation Enzyme-2 (HDAC2) in rats with Chronic Obstructive Pulmonary Disease (COPD), and provided a new direction for drug treatment in the progression of vascular remodeling. Methods Eighteen female SD rats were randomly divided into control (Group S1), COPD (Group S2), and atorvastatin calcium + COPD (Group S3) groups. A COPD rat model was established by passive smoking and intratracheal injection of Lipopolysaccharide (LPS). Haematoxylin and eosin staining and Victoria Blue + Van Gibson staining were used to observe pathological changes in the lung tissue. The pulmonary vascular inflammation score was calculated, and the degree of pulmonary vascular remodeling was evaluated. The ratio of Muscular Arteries in lung tissue (MA%), the ratio of the vessel Wall Area to the vessel total area (WA%), and the ratio of the vessel Wall Thickness to the vascular outer diameter (WT%) were measured using imaging software. The expression of HDAC2 was measured using western blotting, ELISA (Enzyme-Linked Immunosorbent Assay), and qPCR (Real-time PCR). Results Compared with the control group, the degree of pulmonary vascular inflammation and pulmonary vascular remodeling increased in rats with COPD. The WT%, WA%, and lung inflammation scores increased significantly; the expression of HDAC2 and HDAC2mRNA in the serum and lung tissue decreased, and the level of Vascular Endothelial Growth Factor (VEGF) in the lung tissues increased (p< 0.05). Compared with the COPD group, the lung tissues from rats in the atorvastatin group had fewer inflammatory cells, and the vascular pathological changes were significantly relieved. The WT%, WA%, and lung inflammation scores decreased significantly; the expression of HDAC2 and HDAC2mRNA in the serum and lung tissues increased, and the level of VEGF in the lung tissues decreased (p< 0.05). Conclusion The present study revealed that atorvastatin calcium could regulate the contents and expression of HDAC2 in serum and lung tissues and inhibit the production of VEGF, thereby regulating pulmonary vascular remodeling in a rat model with COPD.

The relationship between endogenous ethylene production and natural defoliation rate was examined in sugarcane cultivars with different natural defoliation traits. Ethylene production was examined at different positions on leaf sheaths and leaf scars at various sugarcane maturation stages using gas chromatography as an external standard method. During the sugarcane maturation process, ethylene production was greatest in the 2nd leaf sheath scar, followed by the 5th and 10th, in that order. It was also greatest during the early maturation stage, followed by the mid-maturation and harvest stages. Ethylene production of the leaf sheaths and leaf scars differed significantly among the sugarcane cultivars. Cultivars that defoliate easily produced significantly more ethylene than those that do not defoliate easily. The natural defoliation rates was greatest in the harvest stage, followed by mid-maturation and early maturation stage. Correlation analysis indicated that ethylene production was positively correlated with natural defoliation rates, particularly during early- and mid-maturation stages.