[Changes of collagen distribution in extrapulmonary arteries of hypoxia-induced pulmonary hypertensive rat]

Changes of collagen distribution in extrapulmonary arteries induced by hypoxia and the effects of ligustrazine (ligus) and 764-3 were investigated. Histological study showed that hypoxia could induce an increase of the medial and adventitial thickness of the pulmonary arterial trunk. An increase of type I and type III collagen fibers in pulmonary arterial trunk, particularly the increase of type III collagen fibers in adventitia of the pulmonary trunk were revealed by picrosirius-polarization methods. Ligus partially prevented the increase of type I and III collagen fibers of pulmonary arterial trunk. Electron microscopy showed that both the medial smooth muscle and adventitial fibroblasts were hypertrophic and hyperplastic, and the surrounding collagen fibers were increased.