Figure 2.

Post-translational processing of proglucagon. HPLC profiles of the patient’s plasma; asterisks indicate the glucagon calibration point. (A, B and C) Immunoreactive glucagon in the HPLC fractions was measured by radioimmunoassays using a ‘side-viewing’ antibody, which recognizes all peptides containing the glucagon sequence as well as antibodies directed against the mature, fully processed terminals of glucagon (C-terminal and N-terminal). (D) Accumulation of cAMP in baby hamster kidney (BHK) cells expressing cloned human glucagon receptors. Cells were stimulated with normal human plasma, patient plasma or charcoal-extracted normal human plasma supplemented with 1 nM glucagon. Shown are means and standard deviations of quadruple determinations.