The Effect And Mechanism Of Felodipine On Monocrotaline Induced Pulmonary Hypertension In Rats

The effect and mechanism of felodipine on monocrotalineinduced pulmonary hypertension in ratsAbstractObjective To explore the effect and the mechanism of felodipine on the pulmonary hypertension (PH). Adult male Wistar rats were given a single subcutaneous monocrotaline(MCF, 60mg/kg) to induce the mold of PH. Methods Felodipine(Smg/kg) was administered intraperitoneally every day after MCI?injection for 4 weeks. The parameters of pulmonary hemod~namics were monitored. The concentrations of endothelin-like immunoreactivity(ir-ET~, Calcitonin Gene-Related Peptide(CGRP) in plasma and heart.. pulmonary tissue were measured by radioimmunoassary and colorimetric analysis .Medial thickness of the small pulmonary artery was calculated. Right ventricle myocardium tissue was obseived under the electron microscope. Results Continuous injection of felodipine significantly inhibited the progression of pulmonary artery pressure (44.60 ?4. 38 mml-lg versus 20. 3 ?2. 11 nmHg).Histological examination reveal that felodipine also effectively prevented pulmonary arterial medial thickening. Felodipine significantly raised concentration of CGRP in plasma (83.48?18. 50 pg ml?versus 149.36 ?1. 22 pg ml?.. pulmonary homogenate (22.90?. 56 pg ml?VC1~SUS 29.0131 pg ?ml? and myocardium homogenate(17.88?1.62 pg n11 versus23.50?. 91 pg m1~?. But Ef had no change in the heart.. pulmonary tissue. Furthermore it could decrease the right ventricle myocardiuni damage. ConclusionsContinuously using felodipine can effectively prevent pulmonary hypertension induced by M(T of which mechanism may be partly related to the increase in the concentration of the CGRP besides its inhibition of inflow of Qi2~ The results indicate that felodipine should be considered for clinical trials in treatment of primaiy pulmonary hypertension in humans.