Figure 4 - Whole body radioautographs showing the distribution of total (A) and nonspecific (B) glucagon-binding sites in mice 3 min after intravenous injection of 185 kBq ¹²⁵I-glucagon. ¹²⁵I-glucagon (3-[¹²⁵I]iodotyrosyl¹⁰glucagon dissolved in Ringer solution at a concentration of 185 kBq/0.4 ml) was injected into the tail vein in the absence (A) or presence (B) of excess (25 µg) unlabeled glucagon. Bar = 1 cm.