Preserved incretin activity of glucagon-like peptide 1 (7 - 36)amide but not of synthetic human gastric inhibitory polypeptide in patients with type 2 diabetes mellitus. - Nauck,M.A.; Heimesaat,M.M.; Orskov,C.; Holst,J.J.; Ebert,R.; Creutzfeldt,W. (J Clin Invest, 1993)