Gastric emptying of liquids and solids in the portal hypertensive rat

The effects of portal hypertension on gastric motor function were investigated using the rat staged portal vein ligation model. Gastric emptying of liquids and solids was studied separately following meals labeled with⁵¹Cr or⁹⁹Tc by whole stomach scintillation counting. Portal hypertension was consistently established in experimental rats (splenic pulp pressure: mean±SEM, portal hypertension versus control, 16.8 ±0.7 vs 11.8 ±0.7 mm Hg, P <0.0001). Although liquids were emptied in an exponential manner and solids in a linear fashion, gastric emptying of both meals was more rapid in the experimental rats. Ten minutes after the liquid meal, more than 50% of the meal had emptied from the stomachs of portal hypertensive rats while only one third of the meal had cleared in the control group (P<0.02). Gastric emptying of the solid meal was significantly accelerated in experimental rats at 60 and 120 min (percent meal remaining: portal hypertension versus control, 41.9±4.0 vs 55.4±3.5 and21.5±4.9 vs 32.6±4.3, P<0.05). Stomachs of portal hypertensive animals were heavier (P<0.009) and histologic examination revealed submucosal edema. Thus, a possible mechanism of the disrupted gastric motor function in portal hypertension is decreased gastric wall compliance secondary to edema.