LIGHT AND ELECTRON-MICROSCOPIC IMMUNOCYTOCHEMICAL DEMONSTRATION OF THE COEXISTENCE OF SOMATOSTATIN-14-LIKE AND SOMATOSTATIN-25-LIKE PEPTIDES IN ENDOCRINE-CELLS OF THE STOMACH OF SPARUS-AURATA (TELEOST)

An immunofluorescence double-staining method colocalized somatostatin 14 (SST 14)- and somatostatin 25 (SST 25)-like immunoreactivities in endocrine cells located in the depth of gastric folds and upper part of the stomach glands of Sparus aurata (gilthead sea bream). An immunogold method identified somatostatin-like peptides in the secretory granules of the previously described Type IV endocrine cells. Appropriate preabsorption controls demonstrated two different granule populations with somatostatin-like immunoreactivity. SST 14-like peptides seemed to be located in the most commonly found granules, which showed a fibrillar content, whereas SST 25-like peptides were identified in more scarce and denser granules. © 1991.