Inhibition of Human Gastric Lipase Secretion by Glucagon-like Peptide-1

Glucagon-like peptide-1 (GLP-1) may be one ofthe enterogastrone hormones of the ileal brakemechanism. We therefore studied its effects on gastriclipase secretion in healthy volunteers and vagotomized patients during infusion of pentagastrin. Theintestinal incretin hormone GLP-1 (glucagon-likepeptide-1, 7-36 amide) was investigated because of itsinhibitory effects on gastric acid secretion andmotility. GLP-1 infused intravenously in amountscorresponding to the postprandial release significantlyinhibited pentagastrinstimulated gastric lipasesecretion and lipolytic activity. The inhibitory effectof GLP-1 persisted in vagotomized patients,suggesting that fundic chief cells, from which gastriclipase is released, or neighboring inhibitory cellscould be equipped with GLP-1 receptors. Vagotomizedpatients had significantly higher plasma concentrationsof gastrin and secretin. No significant changes ofgastrin, secretin, and CCK secretion were seen duringGLP-1 infusion in the vagotomized patients, whereas secretin decreased significantly in the healthyvolunteers. GLP-1 seems to be a naturally occurringinhibitor of gastric lipase secretion acting via anonvagal mechanism. Our results indicate that gastric lipase secretion is subject to hormonalstimulatory as well as inhibitory mechanisms.