Effect of synthetic prostaglandin E1 analog (ornoprostil) on gastric emptying and pancreatic polypeptide release after solid-meal ingestion in man

The effect of orally administered ornoprostil, 17S,20-dimethyl-6-oxoprostaglandin E₁ methyl ester, on gastric emptying and on pancreatic polypeptide (PP) release after solid meal ingestion, was investigated in man. A radionuclide technique was used to measure gastric emptying of eight healthy volunteers. In addition, four parameters [SI (starting index): the lag time in the start of emptying;K value: the emptying rate;T1/2: the half emptying time; 120 min RR: the percent retention at 120 min] were determined for evaluation. Also, the PP response was analyzed according to two parameters: IPPR_SI, the integrated PP response for periods up to SI, and IPPR₁₂₀, the integrated PP response for 120 min. The results demonstrated that 5 g of orally administered ornoprostil significantly reduced the gastric emptying rate of solid meal (T1/2 and 120 min RR,P<0.05). However, ornoprostil affected neither the basal PP concentrations nor the cephalic phase of PP secretion which was determined as IPPR_SI. This thus suggests that ornoprostil affects the gastric motor function without interfering with the vagal-cholinergic pathway to the stomach.