Experimental Production of Pulmonary Hypertension and Pulmonary Atherosclerosis in the Rabbit

Abstract

The experimental production of pulmonary atherosclerosis was studied in 39 rabbits. Variables examined included age, pulmonary hypertension after pneumonectomy, and high-fat diet. Right ventricular pressures were measured and then stress-strain elasticity measurements and histologic examination were made of the pulmonary arteries. High-fat diet alone produced neither right ventricular hypertension nor pulmonary atherosclerosis. Right ventricular hypertension occurred after pneumonectomy alone, but there were no anatomic changes unless the rabbits had eaten a high-fat diet. Pneumonectomy plus a high-fat diet was followed by persistent hypertension with right ventricular systolic pressures more than twice control values and by progressive pulmonary atherosclerosis consisting of discrete atheromata in the larger vessels and intimal fibrosis in the smaller arteries. No pathologic or physiologic differences were observed between the changes in the older (24 months) rabbits and the younger (6 months) ones, except in the measurements of elasticity. The old rabbit's pulmonary artery strip is slightly less extensible than that of the young rabbit, but pneumonectomy and high-fat diet did not reduce extensibility further. These preparations may serve adequately for the experimental study of pulmonary atherosclerosis.