Article Text

PDF

Evagination of smooth muscle cells in the hypoxic pulmonary trunk.
  1. P Smith,
  2. D Heath,
  3. F Padula

    Abstract

    Six female Wistar albino rats were exposed to the hypoxia of a simulated altitude of 5500 m, three for a period of one week and three for a month. They developed ultrastructural changes in the pulmonary trunk consisting of evaginations of muscle cells of its media through gaps in the internal elastic lamina to press into the underlying endothelial cells. Such evaginations were usually devoid of myofilaments and organelles. Some appeared so electron-lucent as to be unrecognisable as muscle apart from the unequivocal connection with the parent smooth muscle cells. Elsewhere we have demonstrated that muscular evaginations in normal pulmonary blood vessels are an artefact brought about by collapse of lung tissue and that they can be avoided by distending the lung. Hence in the present investigation, in which the pulmonary trunk was fixed in distension, the evaginations are interpreted as indicating contraction of the muscle cells able to overcome the distending force. We interpret them as evidence of constriction of muscle cells in the media of the pulmonary trunk in response to hypoxia.

    Statistics from Altmetric.com

    Request permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.