Octreotide ameliorates the increase in collateral blood flow during postprandial hyperemia in portal hypertensive rats

Background/Aims: The aims of this study were to examine, in a conscious rat model of portal hypertension, the effect of postprandial splanchnic hyperemia on collateral blood flow and to determine whether octreotide has an effect on postprandial collateral flow changes. Methods: In rats with portal vein ligation, pulsed-Doppler flowmeters were implanted chronically around the splenorenal venous shunt (SRS), which is the main spontaneous collateral vessel in the portal hypertensive rat and around the superior mesenteric artery (SMA). Changes in flow after a standard liquid meal gavage and after the administration of octreotide were examined in the rat under unanesthetized and unrestricted conditions. Results: SRS flow increased significantly after gavage with a standard liquid meal (10.6±2.9%) compared to orogastric intubation alone (−6.5±2.1%) (P<0.01). Similar flow changes were observed in the SMA after liquid meal gavage. The subcutaneous administration of octreotide at a dose of 400 μg/kg reduces basal SRS flow (−19.5±2.3%) and significantly attenuated the change in SRS flow after liquid meal gavage (−8.1±2.9%) compared to animals that received placebo (3.6±4.1% and 27.8±7.6%, respectively) (P<0.05). Conclusions: These results demonstrate that, in an experimental model of prehepatic portal hypertension, postprandial splanchnic hyperemia results in an increase in collateral flow that can be ameliorated with the use of octreotide.