Chronic Pulmonary Hypertension in Sheep: Temporal Progression of Lesions

• Published in: The Journal of surgical research 1996-05, Vol.62 (2), p.243-250
• Main Authors: Schnader, Jeff, Schloo, Betsy L., Anderson, William, Stephenson, Larry W., Fishman, Alfred P.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Factor VIII - metabolism; Female; Hemodynamics; Hypertension, Pulmonary - pathology; Lung - pathology; Male; Medical sciences; Pneumology; Pulmonary Artery - pathology; Pulmonary hypertension. Acute cor pulmonale. Pulmonary embolism. Pulmonary vascular diseases; Sheep; Time Factors; Vasculitis - pathology
• ISSN: 0022-4804; 1095-8673
• DOI: 10.1006/jsre.1996.0202

Scant data exist on the evolution of the lesions of pulmonary hypertension. This study establishes a model in sheep in which the left upper lobe (LUL) was rendered hypertensive by a systemic–pulmonary shunt while the rest of the pulmonary circulation remained normotensive. By examining lung tissue at 2 months and 112 years after shunting, we sought the temporal progression of pulmonary hypertensive lesions. In the hypertensive LULs (n= 5), many vascular lesions were seen in contrast to the absence of lesions in both the contralateral normotensive lungs (n= 5) and the “control” lungs from sheep which underwent thoracotomy without shunting (n= 5). Vascular necrosis and vasculitis were present after 2 months (P< 0.01) but disappeared after 112 years. In contrast, intimal thickening was present after 112 years (n= 2,P< 0.01) but not significantly after 2 months. These intimal lesions often demonstrated increased cellularity staining positively for factor VIII. Plexiform lesions were present at 2 months (P< 0.05) but were more profuse after 112 years (P< 0.01). These findings are consistent with an early vascular injury and a later remodeling or reparative process in hemodynamic pulmonary hypertension.