title: Non-invasive imaging of the endocrine pancreas (review).
abstract: The non-invasive imaging of the endocrine pancreas is currently considered by concerned institutions as a priority theme of research. Because the endocrine pancreas represents only about one percent of the pancreatic gland, highly specific tools are required for labelling the insulin-producing cells. The present review deals with the possible use of D-mannoheptulose for the non-invasive quantification of insulin-producing cells in the pancreas. This heptose is transported into hepatocytes and insulin-producing cells, but not other cell types, at the intervention of GLUT2. Its uptake coincides with the intracellular accumulation of acidic metabolites generated by phosphorylation of D-mannoheptulose. These metabolites remain in the islet cells after prolonged washing, suggesting that imaging of the pancreas at a relatively late time after intravenous administration of D-mannoheptulose could avoid significant extracellular contamination. Using tritiated D-mannoheptulose as tracer, a new method was designed for quantification of the total mass of insulin-producing cells in either isolated perfused rat pancreata or isolated pancreatic islets. Likewise, a preferential labelling of hepatocytes and insulin-producing transplanted cells can be achieved in vivo after administration of tritiated D-mannoheptulose. In the light of results obtained with 6-deoxy-6-iodo-D-glucose, it is proposed that 7-deoxy-7-iodo-D-mannoheptulose could be used for the non-invasive imaging of the endocrine pancreas.
authors.affiliation: Laboratory of Experimental Hormonology, Brussels Free University, B-1070 Brussels, Belgium. malaisse@ulb.ac.be
authors.forename: Willy J
authors.initials: WJ
authors.lastname: Malaisse
mesh_terms: D000818:Animals; D003952:Diagnostic Imaging / Q000379:methods*; D051273:Glucose Transporter Type 2; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000378:metabolism / Q000473:pathology; D008356:Mannoheptulose / Q000378:metabolism; D008954:Models, Biological; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D010179:Pancreas / Q000473:pathology*; D051381:Rats
chemical_list: D051273:Glucose Transporter Type 2; D007328:Insulin; D009004:Monosaccharide Transport Proteins; D008356:Mannoheptulose