IMMUNOHISTOCHEMICAL LOCALIZATION OF SOMATOSTATIN RECEPTOR SST2A IN THE RAT PANCREAS (VOL 138, PG 2632, 1997)

Somatostatin (SRIF) acts on specific membrane receptors to inhibit exo crine and endocrine pancreatic functions. Five SRIF receptor genes hav e been cloned, producing six receptor proteins (sst-s). We used a rece ntly developed antibody to localize the sst2A splice variant in the ra t pancreas. Western blots identified the sst2A receptor as an 90 kDa g lycosylated protein in pancreatic tissue. In tyramide-amplified immuno stainings all acinar cells, and the glucagon and pancreatic polypeptid e immunoreactive cells (A and PP, respectively) were intensely labeled for sst2A, while no signal was detected in SRIF producing (D) cells. A very few insulin immunoreactive (B) cells were also labeled for sst2 A, but the signal in these cells was lower than in exocrine, A or PP c ells. Absorption of the sst2A antibody with the receptor peptide aboli shed specific staining in both immunoblots and tissue sections (negati ve control). These studies are the first to localize any SRIF receptor subtype in the rat pancreas. The specific localization of sst2A recep tor in acinar, A and PP cells if confirmed in humans, would suggest th at subtype specific analogs will be useful for the therapeutic regulat ion of exocrine and/or endocrine pancreatic secretion.