The mean pulmonary artery pressures of the saline/vehicle and saline/Lodelaben groups are similar, 16.4±1.1 and 17.4±0.9 mm Hg, respectively. Although, mean pulmonary artery pressure in the monocrotaline/vehicle group is 27.5±0.8 mm Hg, treatment of monocrotaline rats with Lodelaben results in significantly lower values (21.00±1.6 mm Hg, p<0.05). Saline/vehicle and saline/Lodelaben rats have only a small percentage of arteries muscularized at the alveolar wall level (1.9±1.4 and 0.4±0.4%, respectively). Treatment of monocrotaline-injected rats with Lodelaben results in a decreased percentage of alveolar wall arteries muscularized (10.0±3.6%)[2].