The role of RhoA/ROCK signaling pathway in a rat model of pulmonary hypertension caused by left heart disease

  Objective: To investigate the expression level and role of RhoA/ROCK signaling pathway in a rat pulmonary hypertension model related to left heart disease.

  Method: 20 male SD rats aged 3~4 weeks, weighing 90~100 g, were randomly divided into control group (group C: n = 10) and pulmonary hypertension group (group H: n = 10). Group H used ascending aorta fixation and constriction to construct a rat model of left heart disease-related pulmonary hypertension. Rats in group C were treated with sham operation (titanium clamps were fixed to the paravascular mediastinum tissue instead of the ascending aorta. Group), 60 days after modeling, the rats in each group were tested for hemodynamics (right ventricular systolic pressure, pulmonary artery pressure), and the rats were sacrificed and in vivo cardiopulmonary lavage with PBS caused both lungs to become white and left lung Tissues were fixed in 4% paraformaldehyde for pathological sections to observe the pathological changes of lung tissues, and the right lung tissues were frozen for biomolecular detection (Rho kinase mRNA, RhoA mRNA, ET-A receptor mRNA).

  Results: Compared with group C, the pulmonary artery pressure and right ventricular systolic pressure in group H were significantly increased (P<0.01), the pulmonary arteriole wall was significantly thickened, the pulmonary arterioles were narrowed or even occluded, and the wall hypertrophy index was significantly increased ( P<0.01); Compared with group C, the expression level of Rho kinase mRNA in the lung tissue of group H increased significantly, and the expression levels of RhoA mRNA and ET-A receptor mRNA also increased significantly, and the differences were statistically significant (P<0.01) .

  Conclusion: A rat model of left heart disease-related pulmonary hypertension was successfully constructed by using ascending aorta fixation and constriction; compared with group C, the walls of small pulmonary blood vessels in group H were significantly thickened, and Rho kinase mRNA, RhoA mRNA, ET in lung tissue -A receptor mRNA expression is significantly increased, this signaling pathway may be involved in the formation of left heart disease-related pulmonary hypertension.