Radioimmunoassay of glucagon released from isolated guinea-pig islets of Langrrhans incubated in vitro

1. 1. An immunoassay for glucagon was devised to measure the release of gucagon from isolated guinea-pig islets of Langerhans. [ 125 I]Glucagon of specific activity 300–350 μC/μg prepared and used in the assay in which antibody-bound glucagon was separated from unbound glucagon by precipitation of the antibody-glucagon complex by 67% ethanol at 4°. 2. 2. Guinea-pig islets, isolated by collagenase digestion of guinea-pig pancreas, wee found to respond to changing concentrations of glucose and amino acids in a way similar to that reported for experiments with other species in vitro and in vivo .