Cytochemical demonstration of somatostatin 28-(1-14)-like immunoreactivity in the rat hypothalamus and gastro-entero-pancreatic endocrine system.
Somatostatin-28 (SS 28) is a NH2-terminally extended form of somatostatin-14 (SS 14). Using an antiserum whose antigenic determinant is contained in segment 1-14 of SS 28, the cellular localization of a SS 28-(1-14)-like immunoreactivity was examined in the hypothalamus and gastro-enteropancreatic endocrine system of the rat. Immunoreactivity for SS 28-(1-14) was recognized in the SS 14-immunoreactive nerve cells of the hypothalamus and their axons terminating in the median eminence. Electron microscopic immunocytochemistry revealed that SS 28-(1-14)-like immunoreactivity in the median eminence was localized in the secretory granules of a type of nerve terminal. The immunoreactive cells in the gastro-enteropancreatic endocrine system also corresponded to the SS 14-immunoreactive D cells. Only in the pyloric antrum, however, did SS 14-immunoreactive D cells show no or very weak reactivity to the anti-SS 28-(1-14) serum. The wide distribution of SS 28-(1-14)-like immunoreactivity in the same cellular elements as those containing SS 14 supports the view that SS 28 is a precursor of SS 14.
D000818:Animals; D004064:Digestive System / Q000032:analysis*; D006651:Histocytochemistry; D007031:Hypothalamus / Q000032:analysis*; D007158:Immunologic Techniques; D008297:Male; D008854:Microscopy, Electron; D010179:Pancreas / Q000032:analysis*; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000032:analysis*; D053561:Somatostatin-28
D013004:Somatostatin; D053561:Somatostatin-28