[Hyperdynamic status in a partial portal vein ligated (PVL) rat's portal hypertension model].
The splanchnic and systemic hemodynamics were measured by radioactive microsphere techniques in a PVL rat's model with portal hypertension. The portal-hypertensive rats (1.75 +/- 0.24 vs. 1.23 +/- 0.13 kPa, P < 0.001) with greater than 93% portal-systemic shunting had an increase in portal venous inflow by 50% (8.97 +/- 0.8 vs. 6.03 +/- 0.28 ml.min-1.100gBW-1; P < 0.001) and a concomitant decrease by 40% in splanchnic arteriolar resistance (0.27 +/- 0.05 vs. 0.42 +/- 0.05kPa.ml-1.min-1.100gBW-1; P < 0.01) compared with control rats. Cardiac index (54.6 +/- 4.4 vs. 36.5 +/- 3.0 ml.min-1.100gBW-1) was elevated by 50% (P < 0.001), and total peripheral resistance (0.052 +/- 0.006 vs. 0.084 +/- 0.009 kPa.ml-1.min-1.100gBW-1) was decreased by 40% (P < 0.001). The resistance to portal blood flow in portal vein-stenotic rats (0.087 +/- 0.011kPa.ml-1.min-1) was similar to that in control rats (0.076 +/- 0.01kPa.ml-1.min-1), indicating that the hyperdynamic portal venous inflow, not resistance, was the mainstay of the elevated portal venous pressure. Which is in favor of the forward flow theory of portal hypertension. The systemic hemodynamic parameters were secondary to the splanchnic hemodynamic changes.