Journal of Applied Physiology, Vol 56, Issue 3 810-815, Copyright © 1984 by American Physiological Society
A model of embolic chronic pulmonary hypertension in the dog
I. Shelub, A. van Grondelle, R. McCullough, S. Hofmeister and J. T. Reeves
Despite numerous efforts, a reliable model of chronic embolic pulmonary
hypertension has not been established. To develop such a model five
conscious mongrel dogs were embolized repeatedly over 16-30 wk with
Sephadex microspheres 286 +/- 70 micron in diameter. Hemodynamic and
respiratory measurements were obtained just prior to each embolization.
Chronic pulmonary hypertension developed in all dogs. Pulmonary
hypertension was not accounted for by increased cardiac output, wedge
pressure, right atrial pressure, or systemic arterial pressure. Gas
exchange was little altered. Lung histological study revealed microspheres
clustered within vessels. In three dogs increased pulmonary arterial
pressure was sustained despite cessation of embolization for up to 5 mo.
Reembolization in one of these caused further pulmonary hypertension. In
two dogs acute pulmonary vasodilation by O2 breathing and administration of
prostaglandin E1 reduced, but did not abolish, the increased pulmonary
vascular resistance, suggesting some vascular tone was present. An embolic
model of chronic pulmonary hypertension in awake dogs allows further
investigation into the evolution of pulmonary hypertension.
