Identification of the pancreatic endocrine cells of Pseudemys scripta elegans by immunogold labeling.
The endocrine pancreatic cells of Pseudemys scripta elegans were investigated immunocytochemically by light and electron microscopy. Insulin-, somatostatin (SST)-1, SST-28 (1-12)-, salmon (s)SST-25-, glucagon-, pancreatic polypeptide (PP)-, peptide tyrosine tyrosine (PYY)-, and neuropeptide tyrosine (NPY)-like immunoreactivities were observed. Insulin cells were immunogold labeled with bonito insulin antiserum and secretory granules were characterized by a wide halo and a dense core of varying shape. Consecutive PAP-immunostained sections showed that SST-28 (1-12), SST-14, and sSST-25 immunoreactivities occurred in the same cells. However, preabsorption tests demonstrated that anti-sSST-25 serum detected the invariant SST-14 molecule. The SST-28 (1-12)/SST-14-immunogold-labeled cells mainly had round or ovoid medium electron-dense granules. Glucagon-IR cells were characterized by round secretory granules with an electron-dense core, with or without a narrow clear halo. There were PP, PYY, and NPY (NPY-like) immunoreactivities in a population of glucagon-IR cells in the pancreatic duodenal region (glucagon/NPY cells). Most of the secretory granules of these glucagon/NPY-like cells had an electron-dense content and were round, although there were also pyriform or ovoid secretory granules which were smaller than those of glucagon-IR cells. Preabsorption tests proved that the NPY-like peptides detected in the endocrine pancreas of P. scripta elegans were more similar to NPY or PYY than to PP.
Lozano
M T
MT
Department of Cell Biology, University of Murcia, Murcia, 30100, Spain.
García Hernández
M P
MP
García Ayala
A
A
Elbal
M T
MT
Agulleiro
B
B
D000818:Animals; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D010187:Pancreatic Hormones / Q000378:metabolism; D014426:Turtles / Q000033:anatomy & histology* / Q000502:physiology*
D010187:Pancreatic Hormones