Positron emission tomography ligand [11C]5-hydroxy-tryptophan can be used as a surrogate marker for the human endocrine pancreas.
In humans, a well-developed serotonin system is localized to the pancreatic islets while being absent in exocrine pancreas. Assessment of pancreatic serotonin biosynthesis could therefore be used to estimate the human endocrine pancreas. Proof of concept was tested in a prospective clinical trial by comparisons of type 1 diabetic (T1D) patients, with extensive reduction of β-cells, with healthy volunteers (HVs). C-peptide-negative (i.e., insulin-deficient) T1D subjects (n = 10) and HVs (n = 9) underwent dynamic positron emission tomography with the radiolabeled serotonin precursor [(11)C]5-hydroxy-tryptophan ([(11)C]5-HTP). A significant accumulation of [(11)C]5-HTP was obtained in the pancreas of the HVs, with large interindividual variation. A substantial and highly significant reduction (66%) in the pancreatic uptake of [(11)C]5-HTP in T1D subjects was observed, and this was most evident in the corpus and caudal regions of the pancreas where β-cells normally are the major constituent of the islets. [(11)C]5-HTP retention in the pancreas was reduced in T1D compared with nondiabetic subjects. Accumulation of [(11)C]5-HTP in the pancreas of both HVs and subjects with T1D was in agreement with previously reported morphological observations on the β-cell volume, implying that [(11)C]5-HTP retention is a useful noninvasive surrogate marker for the human endocrine pancreas.
Department of Medicinal Chemistry, Preclinical PET Platform, Uppsala University, Uppsala, Sweden olof.eriksson@pet.medchem.uu.se.
Olof
O
Eriksson
Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
Daniel
D
Espes
Department of Medicinal Chemistry, Preclinical PET Platform, Uppsala University, Uppsala, Sweden.
Ram K
RK
Selvaraju
Department of Radiology, Oncology, and Radiation Sciences, Uppsala University, Uppsala, Sweden.
Emma
E
Jansson
Department of Radiology, Oncology, and Radiation Sciences, Uppsala University, Uppsala, Sweden.
Gunnar
G
Antoni
Department of Radiology, Oncology, and Radiation Sciences, Uppsala University, Uppsala, Sweden.
Jens
J
Sörensen
Department of Radiology, Oncology, and Radiation Sciences, Uppsala University, Uppsala, Sweden.
Mark
M
Lubberink
Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.
Ali-Reza
AR
Biglarnia
AstraZeneca R&D, Mölndal, Sweden Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
Jan W
JW
Eriksson
Department of Radiology, Oncology, and Radiation Sciences, Uppsala University, Uppsala, Sweden.
Anders
A
Sundin
Department of Radiology, Oncology, and Radiation Sciences, Uppsala University, Uppsala, Sweden.
Håkan
H
Ahlström
Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
Barbro
B
Eriksson
Department of Radiology, Oncology, and Radiation Sciences, Uppsala University, Uppsala, Sweden AstraZeneca R&D, Mölndal, Sweden.
Lars
L
Johansson
Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
Per-Ola
PO
Carlsson
Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
Olle
O
Korsgren
D006916:5-Hydroxytryptophan / Q000008:administration & dosage*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002250:Carbon Radioisotopes / Q000008:administration & dosage*; D003922:Diabetes Mellitus, Type 1 / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007515:Islets of Langerhans / Q000000981:diagnostic imaging* / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D055815:Young Adult
D002250:Carbon Radioisotopes; D006916:5-Hydroxytryptophan