Figure 6.

Radioimmunoassay of somatostatin-related peptides in pancreas extracts. (A) Schematic depiction of islet vs. intestinal processing of prosomatostatin (44). Indicated peptides are prosomatostatin 1–64, somatostatin 28 [SS-28, prosomatostatin-(65–92)], somatostatin 28(1–12) [prosomatostatin-(65–76)], and somatostatin 14 [SS-14, prosomatostatin-(79–92)]. The cleaved sites are indicated by arrows, with the sequence surrounding the site shown above or below the arrow. (B) Gel filtration of extracts of wild-type and SPC2^−/− pancreas analyzed by radioimmunoassay for somatostatin (RIK 8001; Peninsula Laboratories). This somatostatin antibody crossreacts with both SS-28 and prosomatostatin. ○ indicate wild-type extract and • indicate SPC2^−/− pancreas extract. The arrows show the elution positions of SS-28 and SS-14.