Radioiodinated naphthylalanine derivatives targeting pancreatic beta cells in normal and nonobese diabetic mice.
An imaging method capable of using a signal from pancreatic beta cells to determine their mass would be of immense value in monitoring the progression of diabetes as well as response to treatment. Somatostatin receptors (SSTRs) are expressed on beta cells and are a potential target for imaging. The main objective of this study was to investigate whether pancreatic beta cells are a target for radiolabeled naphthylalanine derivatives. The molecules were subjected to in vitro and ex vivo evaluations. Pancreatic uptake of radioactivity was lower in nonobese diabetic (NOD) mice than normal mice at all time points investigated (P < .05) and correlated with the number of islets in tissue sections of both control and NOD mice. Immunohistochemical and confocal fluorescent microscopic studies showed colocalization of insulin and the conjugate radioligand in the pancreas. The results demonstrated that pancreatic uptake is receptor-mediated, and that beta cells are the primary target.
Amartey
John K
JK
Cyclotron and Radiopharmaceuticals Department, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh 11211, Saudi Arabia. amarty@kfshrc.edu.sa
Shi
Yufei
Y
Al-Jammaz
Ibrahim
I
Esguerra
Celestina
C
Al-Otaibi
Basem
B
Al-Mohanna
Futwan
F
D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D007150:Immunohistochemistry; D007328:Insulin / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000378:metabolism* / Q000473:pathology; D007457:Iodine Radioisotopes; D007700:Kinetics; D051379:Mice; D008808:Mice, Inbred CBA; D016688:Mice, Inbred NOD; D018613:Microscopy, Confocal; D011869:Radioligand Assay; D017481:Receptors, Somatostatin / Q000235:genetics / Q000378:metabolism*; D013004:Somatostatin / Q000031:analogs & derivatives / Q000378:metabolism; D013194:Staining and Labeling / Q000379:methods*; D046509:Tissue Culture Techniques; D014162:Transfection; D015091:beta-Alanine / Q000031:analogs & derivatives* / Q000378:metabolism
D007328:Insulin; D007457:Iodine Radioisotopes; D017481:Receptors, Somatostatin; C121799:somatostatin 14, Tyr(11)-; C101130:somatostatin receptor type 1; D015091:beta-Alanine; D013004:Somatostatin; C063914:beta-naphthylalanine; C093733:somatostatin receptor 2