Introduction:
Animal models have been used to understand the pathophysiology of
pulmonary hypertension, to describe the mechanisms of action and to evaluate promising active
ingredients. The monocrotaline-induced pulmonary hypertension model is the most used animal
model. In this model, invasive and non-invasive hemodynamic variables that resemble human
measurements have been used. Aim: To define if non-invasive variables can predict hemodynamic
measures in the monocrotaline-induced pulmonary hypertension model.
Materials and Methods:
Twenty 6-week old male Wistar rats weighing between 250-300g from the
bioterium of the Universidad del Valle (Cali - Colombia) were used in order to establish that the
relationships between invasive and non-invasive variables are sustained in different conditions
(healthy, hypertrophy and treated). The animals were organized into three groups, a control group
who was given 0.9% saline solution subcutaneously (sc), a group with pulmonary hypertension
induced with a single subcutaneous dose of Monocrotaline 30 mg/kg, and a group with pulmonary
hypertension with 30 mg/kg of monocrotaline treated with Sildenafil. Right ventricle ejection
fraction, heart rate, right ventricle systolic pressure and the extent of hypertrophy were measured.
The functional relation between any two variables was evaluated by the Pearson correlation
coefficient.
Results:
It was found that all correlations were statistically significant (p <0.01). The strongest
correlation was the inverse one between the RVEF and the Fulton index (r = -0.82). The Fulton index
also had a strong correlation with the RVSP (r = 0.79). The Pearson correlation coefficient between
the RVEF and the RVSP was -0.81, meaning that the higher the systolic pressure in the right
ventricle, the lower the ejection fraction value. Heart rate was significantly correlated to the other
three variables studied, although with relatively low correlation.
Conclusion:
The correlations obtained in this study indicate that the parameters evaluated in the
research related to experimental pulmonary hypertension correlate adequately and that the
measurements that are currently made are adequate and consistent with each other, that is, they have
good predictive capacity.