Rats with chronic
portal hypertension have an increased gastric mucosal blood flow and an impaired
acid secretory response to
pentagastrin stimulation. This study investigated the effects of
propranolol, a
drug widely used in the treatment of
portal hypertension, on gastric mucosal blood flow and
acid secretion in portal hypertensive rats with partial portal vein occlusion. In study I, gastric mucosal blood flow, measured by
hydrogen gas clearance, and
acid output were determined in basal conditions and after the administration of
propranolol (0.3 mg/kg/min) or vehicle infusion in portal hypertensive and
sham-operated rats. Gastric mucosal blood flow was significantly higher (p less than 0.005) in portal hypertensive rats than in
sham-operated rats, and it was significantly reduced (p less than 0.05) after
propranolol infusion in portal hypertensive rats (39 +/- 2 vs. 35 +/- 3 ml/min/100 gm). Basal
acid output was not significantly modified with
propranolol infusion, either in portal hypertensive or
sham-operated animals. In study II,
acid output was measured in portal hypertensive rats in basal conditions, during
pentagastrin (20 micrograms/kg/hr) infusion and after the combined infusion of
pentagastrin and
propranolol (or vehicle).
Pentagastrin infusion significantly increased (p less than 0.001)
acid output, but
propranolol did not modify stimulated gastric acid secretion. In conclusion,
propranolol induced a slight but significant reduction in gastric mucosal blood flow and did not change basal or stimulated gastric acid secretion.