title: Tissue-type plasminogen activator in somatostatin cells of rat pancreas and hypothalamus.
abstract: Plasminogen activators (PAs) proteolytically convert plasminogen to plasmin, which, in turn, can degrade most proteins. This system has been implicated in a variety of biological processes. Using immunocytochemical methods, we here describe the localization of tissue-type PA (t-PA) in rat somatostatin cells. In the pancreatic islets, a low number of strongly t-PA-immunoreactive cells was found. By sequential staining, we found these cells to constitute a subpopulation of the somatostatin cells. Biochemical analysis of extracts from isolated rat islets demonstrated the presence of t-PA, and immunoblotting analysis demonstrated one band with a similar electrophoretic mobility. No urokinase-type PA immunoreactivity was found in the rat endocrine pancreas. A granular t-PA immunoreactivity resembling that found in adjacent sections with somatostatin antiserum was found in the median eminence of the hypothalamus. No t-PA immunoreactivity could be detected in somatostatin cells of the gastric and intestinal mucosa.
mesh_terms: D000818:Animals; D007031:Hypothalamus / Q000166:cytology* / Q000201:enzymology; D007124:Immunoenzyme Techniques; D007515:Islets of Langerhans / Q000166:cytology* / Q000201:enzymology; D008297:Male; D008473:Median Eminence / Q000166:cytology / Q000201:enzymology; D008970:Molecular Weight; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000032:analysis*; D010959:Tissue Plasminogen Activator / Q000032:analysis*
chemical_list: D013004:Somatostatin; D010959:Tissue Plasminogen Activator