High-affinity GABA uptake in a subpopulation of somatostatin cells in rat pancreas.
The aim of this study was to localize the high-affinity uptake of [3H]-GABA in Langerhans islets of rats aged 2.5, 7.5, and 75 days. On high-resolution autoradiography, cells presenting characteristic somatostatin granules were labeled, whereas others containing similar granules appeared nearly devoid of silver grains. Immunogold detection with antisomatostatin antibodies and high-resolution autoradiography suggested that uptake of GABA is indeed performed by somatostatin cells. To test the heterogeneity of uptake frequency in somatostatin cells, a second approach, coupling immunohistochemistry with anti-somatostatin, anti-PP, anti-glucagon, anti-glicentin, and anti-CCK antibodies, and low-resolution autoradiography, was applied on paraffin sections. It demonstrated that the uptake ability is not characteristic of all the somatostatin cells but of only a subpopulation of them. A few cells not immunoreactive to the anti-somatostatin antiserum also appeared to be able to take up GABA. Moreover, except for a rare few, the PP-glucagon-, glicentin-, and CCK-39-immunoreactive cells were not labeled by autoradiography.
Gilon
P
P
Laboratoire de Biologie Cellulaire, Université Catholique de Louvain, Belgium.
Remacle
C
C
D000818:Animals; D001345:Autoradiography; D002766:Cholecystokinin / Q000032:analysis; D003594:Cytoplasmic Granules / Q000032:analysis / Q000648:ultrastructure; D053771:Glicentin; D005934:Glucagon / Q000032:analysis; D004763:Glucagon-Like Peptides; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000378:metabolism* / Q000648:ultrastructure; D008854:Microscopy, Electron; D010191:Pancreatic Polypeptide / Q000032:analysis; D010446:Peptide Fragments / Q000032:analysis; D011498:Protein Precursors / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000032:analysis*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D010446:Peptide Fragments; D011498:Protein Precursors; D013004:Somatostatin; D005680:gamma-Aminobutyric Acid; D010191:Pancreatic Polypeptide; D004763:Glucagon-Like Peptides; D053771:Glicentin; D005934:Glucagon; D002766:Cholecystokinin