Related Experiment Video
Updated: Dec 6, 2025
The Left Pneumonectomy Combined with Monocrotaline or Sugen as a Model of Pulmonary Hypertension in Rats
Published on: March 8, 2019
Plexiform Lesions in an Experimental Model of Monocrotalin-Induced Pulmonary Arterial Hypertension
Douglas Mesadri Gewehr1,2, Gabriela Rodrigues Salgueiro1,2, Lucia de Noronha3
1Faculdade Evangélica Mackenzie do Paraná (FEMPAR), Curitiba, PR - Brasil.
Background:
The monocrotaline (MCT)-induced pulmonary arterial hypertension model is one of the most reproduced today, presenting as a limitation the absence of plexiform lesions, typical manifestations of the severe disease in humans.
Objective:
To evaluate the severity of MCT-induced pulmonary arteriopathy by pathological findings of lung and heart tissue samples, clinical course and 37-day survival.
Methods:
Fifty male Wistar rats were divided into one of the four groups - control (CG) (n = 10) and three intervention (MCT) groups. The MCT groups received intraperitoneal injection (60 mg/kg) of MCT and remained exposed to the substance for 15 days (G15, n = 10), 30 days (G30, n = 10) and 37 days (G37, n = 20). At the end of each period, the animals were sacrificed, and pulmonary and cardiac tissues were collected for anatomopathological and morphometric analysis. The Kruskal-Wallis test was used, considering a level of significance of 5%.
Results:
In the lungs of MCT animals, lesions related to pulmonary arteriopathy were found, including muscularization of the arterioles, hypertrophy of the middle layer and concentric neointimal lesions. Complex lesions were observed in MCT groups, described as plexiform and plexiform-like lesions. Right ventricular hypertrophy was evidenced by increased thickness and diameter of the cardiomyocytes and a significant increase in the right ventricular wall thickness (p <0.0000).
Conclusion:
The MCT model was able to generate moderate-severe pulmonary arteriopathy associated with secondary right ventricular hypertrophy. The 37-day survival rate was 50%. To our knowledge, this study was the first to note the presence of complex vascular lesions, similar to those observed in patients with severe pulmonary arterial hypertension, in an isolated MCT model. (Arq Bras Cardiol. 2020; 115(3):480-490).
Insights
The monocrotaline (MCT) rat model successfully induced moderate-to-severe pulmonary arteriopathy and right ventricular hypertrophy, including complex vascular lesions previously absent in this model. This study validates its use for pulmonary hypertension research.
Area of Science:
- Cardiovascular Research
- Pulmonary Medicine
- Animal Models
Background:
- The monocrotaline (MCT)-induced model is widely used for pulmonary arterial hypertension (PAH) research.
- A key limitation has been the absence of plexiform lesions, characteristic of severe human PAH.
Purpose of the Study:
- To assess the severity of MCT-induced pulmonary arteriopathy.
- To evaluate pathological findings in lung and heart tissues.
- To analyze the clinical course and 37-day survival rate.
Main Methods:
- Fifty male Wistar rats were divided into control and three MCT-treated groups (15, 30, and 37 days).
- Animals received a single intraperitoneal injection of MCT (60 mg/kg).
- Pulmonary and cardiac tissues were analyzed pathologically and morphometrically; survival rates were recorded.
Main Results:
- MCT induced pulmonary arteriopathy with arteriole muscularization, medial hypertrophy, and concentric neointimal lesions.
- Complex vascular lesions, including plexiform and plexiform-like lesions, were observed.
- Significant right ventricular hypertrophy was confirmed by increased cardiomyocyte size and right ventricular wall thickness.
Conclusions:
- The MCT model effectively generates moderate-to-severe pulmonary arteriopathy with secondary right ventricular hypertrophy.
- This study reports the novel presence of complex vascular lesions in an isolated MCT model, mimicking severe human PAH.
- A 37-day survival rate of 50% was observed in the MCT-treated groups.
