C. Risoe et al., EFFECT OF ENALAPRILAT ON SPLANCHNIC VASCULAR CAPACITANCE DURING ACUTEISCHEMIC HEART-FAILURE IN DOGS, The American journal of physiology, 266(6), 1994, pp. 80002182-80002189
This study investigates the effect of angiotensin- converting-enzyme i
nhibition by intravenous enalaprilat (100 mu g/kg) on splanchnic vascu
lar capacitance during acute left ventricular failure induced by coron
ary microembolization in alpha-chloralose/ urethan anesthetized dogs.
Changes in hepatic and splenic vascular volumes were determined from o
rgan diameters (sonomicrometry) at 15, 30, and 45 min after enalaprila
t injection. Changes in vascular capacitance were assessed from organ
pressure-diameter curves obtained during transient hepatic outflow occ
lusion. Thirty minutes after enalaprilat, hepatic volume was increased
by 52 +/- 14 ml (P < 0.01), and portal and hepatic vein pressures wer
e decreased from 10.2 +/- 0.9 to 8.7 +/- 0.8 mmHg (P < 0.01) and from
3.9 +/- 1.6 to 3.1 +/- 0.7 mmHg (P < 0.05), respectively. Splenic volu
me did not change. Enalaprilat shifted the hepatic pressure-diameter c
urve upward, resulting in a larger hepatic volume at any given pressur
e. Curve intercept was increased, suggesting an increase in unstressed
vascular volume. Curve slope was unchanged. In conclusion, enalaprila
t increased hepatic vascular volume during acute left ventricular fail
ure in dogs. The pressure-diameter curve shift suggests a reduction in
the smooth muscle tone of hepatic capacitance vessels.