Oral Administration of Peptides; Absorption From Gastrointestinal Tract

The study was conducted as a phase I, open, placebo-controlled, dose-escalating study. In part I, six treatments, separated by at least 7 days, were performed in 6 male subjects; treatments consisted of one oral dose of GLP-1(7-36 amide) (0.5, 1.0, 2.0, and 4 mg) or placebo; the last treatment was an intravenous infusion of GLP-1 given for 45 min (0.4 pmol/kg per min infused for 45 min). The treatments were identical in design except for the oral dose of GLP-1. In part II, six oral treatments, separated by at least 7 days, were given in an additional 6 male subjects; treatments consisted of one oral dose of PYY3-36 (0.25, 0.5, 1.0, 2.0, and 4 mg) or placebo; an intravenous infusion of PYY3-36 could not be given as no GMP conform PYY3-36 was available for use in humans. Blood was drawn in regular intervals in EDTA tubes containing aprotinin (500 kIU/ml blood) and a DPP-IV inhibitor for hormone determinations: -30, -15, 0, 15, 30, 45, 60, 75, 90, 120, 150, 180, 240, 300 min.