Journal of Applied Physiology, Vol 49, Issue 5 841-845, Copyright © 1980 by American Physiological Society
Effect of defibrinogenation on lung water accumulation after pulmonary microembolism in dogs
A. Johnson and A. B. Malik
We determined the effects of chronic fibrinogen depletion on the
development of pulmonary edema after pulmonary microembolization. Dogs were
defibrinogenated with a purified fraction of Malayan pitviper venom
(ancrod). Studies were made in four groups: control untreated (group I);
emboli untreated (group II); control defibrinogenated (group III); and
emboli defibrinogenated (group IV). Fibrinogen decreased (P < 0.05) from
570.6 +/- 100.9 to 5.3 +/- 3.1 mg/100 ml in the ancrod-treated groups.
Pulmonary arterial pressure was increased to similar levels in both
embolized groups after infusion of 100-mug-diam nonsiliconized glass beads
into the right atrium. Pulmonary vascular resistance and pulmonary
perfusion pressure were initially increased to similar levels in both
embolized groups, but by 75 min postembolization (PE) both parameters were
higher (P < 0.05) in the defibrinogenated group. The extravascular lung
water-to-bloodless dry lung ratio at 75 min PE of 4.53 +/- 0.24 in group II
was greater than the control value of 2.84 +/- 0.22 in group I (P <
0.05). In contrast, the extravascular lung water-to-bloodless dry lung
ratio of 3.64 +/- 0.09 in group IV was not different from the control value
of 3.38 +/- 0.04 in group III, but was less than 4.53 +/- 0.24 in group II
(P < 0.05). Therefore, chronic defibrinogenation in dogs prevented the
development of pulmonary edema after pulmonary microembolization. The
protective effect may be due to inhibition of the increase in lung vascular
permeability and to a time-dependent reduction in pulmonary microvascular
pressure.
