{"entity": "journal", "iuid": "889243306be848adb3d1f74077366f55", "timestamp": "2026-10-13T19:56:44.760Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/journal/American%20journal%20of%20nuclear%20medicine%20and%20molecular%20imaging.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/journal/American%20journal%20of%20nuclear%20medicine%20and%20molecular%20imaging"}}, "title": "American journal of nuclear medicine and molecular imaging", "issn": "2160-8407", "issn-l": "2160-8407", "publications_count": 4, "publications": [{"entity": "publication", "iuid": "6cf7565d0e724ae691db1eca82d0fd58", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/6cf7565d0e724ae691db1eca82d0fd58.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/6cf7565d0e724ae691db1eca82d0fd58"}}, "title": "[11C]5-Hydroxy-tryptophan model for quantitative assessment of in vivo serotonin biosynthesis, retention and degradation in the endocrine pancreas.", "authors": [{"family": "Lubberink", "given": "Mark", "initials": "M", "orcid": "0000-0001-8324-7399", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/e8c1d9a8e08a40d3b7a694fd293c2400.json"}}, {"family": "Eriksson", "given": "Olof", "initials": "O", "orcid": "0000-0002-2515-8790", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/85991bf00e4b4a26ab15599d25c58601.json"}}], "type": "journal article", "published": "2020-10-15", "journal": {"title": "American journal of nuclear medicine and molecular imaging", "issn": "2160-8407", "volume": "10", "issue": "5", "pages": "226-234", "issn-l": "2160-8407"}, "abstract": "[11C]5-Hydroxy-tryptophan ([11C]5-HTP) is a Positron Emission Tomography marker for serotonergic biosynthesis and degradation, with use in imaging of neuroendocrine tumors and recently also the endocrine pancreas in diabetes. In order to further develop [11C]5-HTP as a quantitative in vivo tool for understanding the mechanisms of serotonin signaling in human pancreas, we aimed to develop a kinetic modeling approach sensitive for changes in serotonin biosynthesis, retention and degradation. Cynomolgus monkeys were examined by [11C]5-HTP PET/CT, either at baseline (n=9) or following intravenous pretreatment with 3 mg/kg carbidopa (Dopa Decarboxylase inhibitor, n=3) or 2 mg/kg clorgyline (Monoamine Oxidase-A inhibitor, n=5). The dynamic tissue uptake was analysed by a 2-tissue compartment model including an efflux mechanism from the second tissue compartment (2TC kloss), which theoretically reproduces the known processing of 5-HTP in neuroendocrine cells. The 2TC kloss model could accurately describe all three modes of tissue kinetics depending on the pretreatment regiment. Rate constant k3 (corresponding to DDC activity) and the macro-parameter Flux (Ki) was decreased (P<0.05) by carbidopa pretreatment, while k2 (corresponding to cellular washout of intact [11C]5-HTP) was increased (P<0.05). The efflux parameter kloss (corresponding to MAO-A activity) was decreased (P<0.05) by pretreatment of clorgyline, while the macro-parameter Flux/Efflux ratio (Ki/kloss) was increased (P<0.0001). We present a compartment model analysis method that can quantitatively assess in vivo pharmacological interactions with several of the key enzymatic steps of the serotonergic biosynthesis in pancreas.", "doi": null, "pmid": "33224618", "labels": {"SciLifeLab Fellow": null, "Olof Eriksson": null}, "xrefs": [{"db": "pmc", "key": "PMC7675115"}], "notes": [], "created": "2023-05-14T14:53:47.354Z", "modified": "2026-09-24T09:32:53.189Z"}, {"entity": "publication", "iuid": "6db3212b9fdd427db2b8bd9c04da1e54", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/6db3212b9fdd427db2b8bd9c04da1e54.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/6db3212b9fdd427db2b8bd9c04da1e54"}}, "title": "Fully automated GMP production of [68Ga]Ga-DO3A-VS-Cys40-Exendin-4 for clinical use.", "authors": [{"family": "Velikyan", "given": "Irina", "initials": "I", "orcid": "0000-0002-3732-8857", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/947ae561cd794e5b94c6736880620287.json"}}, {"family": "Rosenstrom", "given": "Ulrika", "initials": "U", "orcid": "0000-0002-0817-8140", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/ec6820fcb786475d85969630b0b3860b.json"}}, {"family": "Eriksson", "given": "Olof", "initials": "O", "orcid": "0000-0002-2515-8790", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/85991bf00e4b4a26ab15599d25c58601.json"}}], "type": "journal article", "published": "2017-07-15", "journal": {"title": "American journal of nuclear medicine and molecular imaging", "issn": "2160-8407", "volume": "7", "issue": "3", "pages": "111-125", "issn-l": "2160-8407"}, "abstract": "[68Ga]Ga-DO3A-VS-Cys40-Exendin-4/PET-CT targeting glucagon like peptide-1 receptor (GLP-1R) has previously demonstrated its potential clinical value for the detection of insulinomas. The production and accessibility of this radiopharmaceutical is one of the critical factors in realization of clinical trials and routine clinical examinations. Previously, the radiopharmaceutical was prepared manually, however larger scale of clinical trials and healthcare requires automation of the production process in order to limit the operator radiation dose as well as improve tracer manufacturing robustness and on-line documentation for enhanced good manufacturing practice (GMP) compliance. A method for 68Ga-labelling of DO3A-VS-Cys40-Exendin-4 on a commercially available synthesis platform was developed. Equipment such as 68Ge/68Ga generator, synthesis platform, and disposable cassettes for 68Ga-labelling used in the study was purchased from Eckert & Ziegler. DO3A-VS-Cys40-Exendin-4 was synthesized in-house. The parameters such as time, temperature, precursor concentration, radical scavenger, buffer concentration, pH, product purification step were investigated and optimised. Reproducible and GMP compliant automated production of [68Ga]Ga-DO3A-VS-Cys40-Exendin-4 was developed. Exendin-4 comprising methionine amino acid residue was prone to oxidation which was strongly influenced by the elevated temperature, radioactivity amount, and precursor concentration. The suppression of the oxidative radiolysis was achieved by addition of ethanol, dihydroxybenzoic acid and ascorbic acid to the reaction buffer as well as by optimizing heating temperature. The non-decay corrected radiochemical yield was 43\u00b12% with radiochemical purity of over 90% wherein the individual impurity signals in HPLC chromatogram did not exceed 5%. Automated production and quality control methods were established for paving the pathway for broader clinical use of [68Ga]Ga-DO3A-VS-Cys40-Exendin-4.", "doi": null, "pmid": "28721305", "labels": {"Olof Eriksson": null, "SciLifeLab Fellow": null}, "xrefs": [{"db": "pmc", "key": "PMC5511121"}], "notes": [], "created": "2020-10-06T13:46:24.015Z", "modified": "2025-11-17T09:17:17.057Z"}, {"entity": "publication", "iuid": "828640fda961421082598ddb6c3a6cc6", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/828640fda961421082598ddb6c3a6cc6.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/828640fda961421082598ddb6c3a6cc6"}}, "title": "Dosimetry of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 in rodents, pigs, non-human primates and human - repeated scanning in human is possible.", "authors": [{"family": "Selvaraju", "given": "Ram Kumar", "initials": "RK"}, {"family": "Bulenga", "given": "Thomas N", "initials": "TN"}, {"family": "Espes", "given": "Daniel", "initials": "D", "orcid": "0000-0001-8843-7941", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/80736c5043194099992841a2a2a161f9.json"}}, {"family": "Lubberink", "given": "Mark", "initials": "M", "orcid": "0000-0001-8324-7399", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/e8c1d9a8e08a40d3b7a694fd293c2400.json"}}, {"family": "S\u00f6rensen", "given": "Jens", "initials": "J"}, {"family": "Eriksson", "given": "Barbro", "initials": "B"}, {"family": "Estrada", "given": "Sergio", "initials": "S"}, {"family": "Velikyan", "given": "Irina", "initials": "I", "orcid": "0000-0002-3732-8857", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/947ae561cd794e5b94c6736880620287.json"}}, {"family": "Eriksson", "given": "Olof", "initials": "O", "orcid": "0000-0002-2515-8790", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/85991bf00e4b4a26ab15599d25c58601.json"}}], "type": "journal article", "published": "2015-02-15", "journal": {"title": "American journal of nuclear medicine and molecular imaging", "issn": "2160-8407", "volume": "5", "issue": "3", "pages": "259-269", "issn-l": "2160-8407"}, "abstract": "Quantitative PET imaging with [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 has potential use in diabetes and cancer. However, the radiation dose to the kidneys has been a concern for the possibility of repeated imaging studies in humans. Therefore, we investigated the dosimetry of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 based on the biodistribution data in rats, pigs, non-human primates (NHP) and a human.Organ distribution of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 in rats (Male Lewis; n=12; 30, 60, and 80 min) was measured ex vivo. The dynamic uptake of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 in the abdomen was assessed by PET/CT scanning of pigs (male; n = 4, 0-60 min), NHP (Female; cynomolgus; n=3; 0-90 min), and human (female; n=1; 0-40, 100, 120 min).The organ distribution data in each species were extrapolated to those of a human, assuming similar distribution between the species. Residence times were assessed by trapezoidal approximation of the kinetic data. Organ doses (mGy/MBq) and the whole body effective dose (mSv/MBq), was extrapolated by using the OLINDA/EXM 1.1 software. The extrapolated human whole body effective dose was 0.017 \u00b1 0.004 (rats), 0.014 \u00b1 0.004 (pigs), 0.017 \u00b1 0.004 (NHP), and 0.016 (human) mSv/MBq. The absorbed dose to the kidneys was limiting:0.33 \u00b1 0.06 (rats), 0.28\u00b10.05 (pigs), 0.65 \u00b1 0.11 (NHP), and 0.28 (human) mGy/MBq, which corresponded to the maximum yearly administered amounts of 455 (rat), 536 (pig), 231 (NHP), and 536 (human) MBq before reaching the yearly kidney limiting dose of 150 mGy. More than 200 MBq of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 can be administered yearly in a human, allowing for repeated (2-4 times) scanning. This potentially enables longitudinal clinical PET imaging studies of the GLP-1R in the pancreas, transplanted islets, or insulinoma.", "doi": null, "pmid": "26069859", "labels": {"Olof Eriksson": null, "SciLifeLab Fellow": null}, "xrefs": [{"db": "pmc", "key": "PMC4446394"}], "notes": [], "created": "2020-10-06T13:53:32.732Z", "modified": "2025-11-17T09:33:25.651Z"}, {"entity": "publication", "iuid": "a8c9bdf8736e438caa7e064213eee996", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/a8c9bdf8736e438caa7e064213eee996.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/a8c9bdf8736e438caa7e064213eee996"}}, "title": "Dosimetry of [(177)Lu]-DO3A-VS-Cys(40)-Exendin-4 - impact on the feasibility of insulinoma internal radiotherapy.", "authors": [{"family": "Velikyan", "given": "Irina", "initials": "I", "orcid": "0000-0002-3732-8857", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/947ae561cd794e5b94c6736880620287.json"}}, {"family": "Bulenga", "given": "Thomas N", "initials": "TN"}, {"family": "Selvaraju", "given": "Ramkumar", "initials": "R", "orcid": "0000-0001-9219-1497", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/83711532c31f4f1dad8bd6c3495b9c08.json"}}, {"family": "Lubberink", "given": "Mark", "initials": "M", "orcid": "0000-0001-8324-7399", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/e8c1d9a8e08a40d3b7a694fd293c2400.json"}}, {"family": "Espes", "given": "Daniel", "initials": "D", "orcid": "0000-0001-8843-7941", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/80736c5043194099992841a2a2a161f9.json"}}, {"family": "Rosenstr\u00f6m", "given": "Ulrika", "initials": "U", "orcid": "0000-0002-0817-8140", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/ec6820fcb786475d85969630b0b3860b.json"}}, {"family": "Eriksson", "given": "Olof", "initials": "O"}], "type": "journal article", "published": "2015-01-15", "journal": {"title": "American journal of nuclear medicine and molecular imaging", "issn": "2160-8407", "volume": "5", "issue": "2", "pages": "109-126", "issn-l": "2160-8407"}, "abstract": "[(68)Ga]-DO3A-VS-Cys(40)-Exendin-4 has been shown to be a promising imaging candidate for targeting glucagon like peptide-1 receptor (GLP-1R). In the light of radiotheranostics and personalized medicine the (177)Lu-labelled analogue is of paramount interest. In this study we have investigated the organ distribution of [(177)Lu]-DO3A-VS-Cys(40)-Exendin-4 in rat and calculated human dosimetry parameters in order to estimate the maximal acceptable administered radioactivity, and thus potential applicability of [(177)Lu]-DO3A-VS-Cys(40)-Exendin-4 for internal radiotherapy of insulinomas. Nine male and nine female Lewis rats were injected with [(177)Lu]-DO3A-VS-Cys(40)-Exendin-4 for ex vivo organ distribution study at nine time points. The estimation of human organ/total body absorbed and total effective doses was performed using Organ Level Internal Dose Assessment Code software (OLINDA/EXM 1.1). Six more rats (male: n = 3; female: n = 3) were scanned by single photon emission tomography and computed tomography (SPECT-CT). The renal function and potential cell dysfunction were monitored by creatinine ISTAT and glucose levels. The fine uptake structure of kidney and pancreas was investigated by ex vivo autoradiography. Blood clearance and washout from most of the organs was fast. The kidney was the dose-limiting organ with absorbed dose of 5.88 and 6.04 mGy/MBq, respectively for female and male. Pancreatic beta cells demonstrated radioactivity accumulation. Renal function and beta cell function remained unaffected by radiation. The absorbed dose of [(177)Lu]-DO3A-VS-Cys(40)-Exendin-4 to kidneys may limit the clinical application of the agent. However, hypothetically, kidney protection and peptidase inhibition may allow reduction of kidney absorbed dose and amplification of tumour absorbed doses.", "doi": null, "pmid": "25973333", "labels": {"Olof Eriksson": null, "SciLifeLab Fellow": null}, "xrefs": [{"db": "pmc", "key": "PMC4396004"}], "notes": [], "created": "2020-10-06T13:53:10.670Z", "modified": "2026-09-22T12:26:46.148Z"}], "created": "2020-10-06T13:46:24.029Z", "modified": "2020-11-27T13:12:59.250Z"}