AJP - Gastrointestinal and Liver Physiology, Vol 249, Issue 4 528-G532, Copyright © 1985 by American Physiological Society
Effects of pentobarbital sodium anesthesia on splanchnic hemodynamics of normal and portal-hypertensive rats
S. S. Lee, C. Girod, D. Valla, P. Geoffroy and D. Lebrec
To determine the effect of pentobarbital sodium anesthesia on the rat with
portal hypertension due to portal vein stenosis, four groups of rats were
studied. Cardiac output and regional blood flow were measured by
radioactive microspheres in anesthetized and conscious sham-operated and
portal-hypertensive rats. Anesthesia markedly decreased cardiac output in
both sham-operated (109.7 +/- 4.6 vs. 77.8 +/- 1.4 ml/min, P less than
0.001) and portal-hypertensive rats (130.1 +/- 7.6 vs. 93.8 +/- 5.3 ml/min,
P less than 0.01). In spite of this diminution in cardiac output,
pentobarbital did not significantly change absolute blood flow values of
splanchnic organs in either group. However, the fractions of cardiac output
perfusing the splanchnic organs were significantly increased by
pentobarbital in both groups because of the decrease in cardiac output:
sham operated, anesthetized, 22.86 +/- 1.19% vs. conscious, 14.83 +/-
1.02%, P less than 0.001; and portal hypertensive, anesthetized, 26.67 +/-
0.71% vs. conscious, 19.07 +/- 1.44%, P less than 0.001. The hyperdynamic
circulation of the portal vein-stenosed rat compared with the sham-operated
rat continued to manifest itself with significantly increased portal
pressure, cardiac output, and splanchnic blood flow, whether the animal was
anesthetized or awake. We conclude that, despite marked hemodynamic changes
induced by pentobarbital, the rat with portal vein stenosis remains a
useful experimental model of portal hypertension.
