| Abstract: | Objective: To investigate the evolution of pulmonary hypertension, the pathological changes of pulmonaryarteries, and the expression of VEGFmRNA and eNOSmRNA of pulmonary arterial endothelial cells in immature rabbitstreated with intratracheal bleomycin (BLM). Methods: Immature rabbits were divided into control and BLM group. Twoand four weeks after intratracheal normal saline or BLM injection, the systolic, diastolic and mean pulmonary arterypressure (PASP, PADP, MPAP) were measured by micro-catheter; the pathological changes and the expression ofVEGFmRNA and eNOSmRNA of endothelial cells in pulmonary arteries were evaluated by HE and in situ hybridization.Results: Two and four weeks after intratracheal injection of BLM, the PASP, PADP and MPAP increased 53%, 49%, 52%in 2 weeks, and 43%, 89%, 56% in 4 weeks; the wall thickness increased and the cavity in middle and small pulmonaryarteries became narrow; the Thickness Index (TI) and Area Index (AI) increased 25%, 14% in 2 weeks, and 22%, 24% in 4weeks; the level of VEGFmRNA and eNOSmRNA expression decreased 46%, 43% in 2 weeks, and 43%, 51% in 4 weeks.There was no significant difference between 2 weeks and 4 weeks BLM groups. Conclusion: The pulmonary artery pressurewas elevated, the thickness of wall increased and the cavity became narrow in middle and small pulmonary arteries, and thelevel of VEGFmRNA and eNOSmRNA expression in pulmonary arterial endothelial cells decreased in immature rabbitsafter 2 weeks and 4 weeks of intratracheal 4 U/kg BLM injection. |
