Localization of GABA high-affinity binding sites in the pancreas of neonatal rat

The localization of gamma-aminobutyric acid (GABA) high-affinity binding sites was investigated in the exocrine and endocrine pancreas of neonatal rats by means of 3H-GABA autoradiography. GABA-binding was identified on Schwann cells and on the cells of the intralobular excretory ducts. In the endocrine part of the pancreas, no labelling was observed except in peripheral islet cells which, on the basis of their scarcity and distribution, could be somatostatin cells. Furthermore, peri-insular innervation showed considerable labelling.