Journal of Applied Physiology, Vol 57, Issue 6 1824-1828, Copyright © 1984 by American Physiological Society
Pulmonary fibrin microembolism with Echis carinatus venom in dogs: effects of a synthetic thrombin inhibitor
R. C. Schaeffer Jr, S. M. Chilton, T. J. Hadden and R. W. Carlson
We produced pulmonary fibrin microembolism using an infusion of a
prothrombin activator (Echis carinatus venom, 30 min, 0.5 NIH thrombin
equivalent units/kg) in open-chest mongrel dogs. To determine the
nonclotting effects of this venom on edemagenesis we infused an
irreversible thrombin inhibitor, D-phenylalanyl-L-prolyl-L-arginine
chloromethyl ketone (PPACK, 57 nmol X kg-1 X min-1 for 120 min), alone (n =
5) or with venom (Echis + PPACK, n = 5). The control group (n = 5) was
given 1 ml of 0.9% NaCl. A decline in left atrial pressure (means +/- SE,
5.3 +/- 0.4 to 4.0 +/- 0.5 mmHg, P less than 0.05) and cardiac index (149
+/- 10 to 82 +/- 13 ml X min-1 X kg-1, P less than 0.01) in association
with a marked increase in pulmonary arterial pressure (14.5 +/- 0.6 to 26.6
+/- 2.5 mmHg, P less than 0.001) and pulmonary vascular resistance (64 +/-
5 to 304 +/- 42 mmHg X ml-1 X min-1 X kg-1, P less than 0.001) was observed
after 20 min of venom infusion. During this interval, pulmonary artery
wedge pressure increased (4 +/- 1 to 12 +/- 4 mmHg, P less than 0.01) in
four of eight animals. Fibrinogen declined below measurable levels and
fibrin microemboli were seen in many pulmonary arterioles. These changes
were not observed in the Echis + PPACK, PPACK, or control groups.
Leukopenia and thrombocytopenia were observed in the Echis and Echis +
PPACK groups.(ABSTRACT TRUNCATED AT 250 WORDS)
