Inability of Some Commercial Assays to Measure Suppression of Glucagon Secretion

Figure 1

Plasma glucagon levels of five healthy participants during a 6 mmol/L glucose clamp with simultaneous infusion of either saline (black) or atropine (red). (a) depicts assay A, a radioimmunoassay; (b) depicts assay B, a spectrophotometrically based ELISA; (c) depicts assay C, a chemiluminescence based ELISA; and (d) depicts assay D, a homogeneous time-resolved fluorescence based ELISA. Net area under the curve (nAUC) is depicted separately at upper right quadrant on (a), (b), (c), and (d). represents a significant two-sided -test comparing saline nAUC to atropine nAUC. Data illustrated as mean ± standard deviation.

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