Molecular forms of glucagon‐like peptides in man

Abstract
Molecular forms of the glucagon‐like peptides (GLP) encoded by the human preproglucagon gene were analysed by chromatography combined with specific radioimmunoassays to the synthetic peptides. Whereas extracts of human pancreas and a glucagonoma contained a large proglucagon cleavage product possessing both GLP‐1 and GLP‐2 immunoreactivities, extracts of human intestine contained products corresponding to free GLP‐1 and a small amount ofchromatographically distinct GLP‐2 immunoreactivity. It is concluded that post‐translational processing of proglucagon differs in pancreas and intestine, so that the C‐terminal portion of the molecule is cleaved to liberate free GLP‐1 in the intestine. Further processing or degradation results in loss especially of GLP‐2 immunoreactivity.