{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,25]],"date-time":"2025-09-25T16:11:24Z","timestamp":1758816684652,"version":"3.41.2"},"reference-count":44,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,3,3]],"date-time":"2025-03-03T00:00:00Z","timestamp":1740960000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Endocrinol."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>Levodopa (L-3,4-dihydroxyphenylalanine)g, a dopamine precursor that circulates in the peripheral region, is involved in pancreatic glycemic control. Although previous animal studies have shown that peripheral levodopa is correlated with insulin secretion in pancreatic beta cells, the mechanism by which the pancreas uses levodopa differently in humans with obesity and type 2 diabetes remains unknown. Our study aimed to observe how the pancreas uptakes and utilizes levodopa differently under obese and diabetic conditions.<\/jats:p><\/jats:sec><jats:sec><jats:title>Materials and method<\/jats:title><jats:p><jats:sup>18<\/jats:sup>F-fluoro-L-dopa positron emission tomography-computed tomography (<jats:sup>18<\/jats:sup>F-FDOPA PET-CT) was used to visualize how the human body uses levodopa under obese and diabetic conditions and presented its clinical implications. 10 patients were divided into 3 groups: 1) Group A, normal weight without type 2 diabetes; 2) Group B, obese without type 2 diabetes; and 3) Group C, obese with new-onset type 2 diabetes. All patients\u2019 lifestyle modification was conducted prior to <jats:sup>18<\/jats:sup>F-FDOPA PET-CT, and plasma samples were collected to confirm changes in amino acid metabolites.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Pancreatic levodopa uptake increased in obese patients with insulin resistance, whereas it decreased in obese patients with new-onset type 2 diabetes [standardized uptake value (SUV) mean in participants with normal weight, 2.6 \u00b1 0.7; SUV<jats:sub>mean<\/jats:sub> in patients with obesity, 3.6 \u00b1 0.1; SUV<jats:sub>mean<\/jats:sub> in patients with obesity and new-onset type 2 diabetes, 2.6 \u00b1 0.1, P = 0.02].<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>This suggested that the alterations in the functional capacity of pancreatic beta cells to take up circulating levodopa are potentially linked to the insulin resistance and the pathogenesis of type 2 diabetes. The differences in the uptake values between the groups implied that pancreatic levodopa uptake could be an early indicator of type 2 diabetes.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fendo.2025.1460253","type":"journal-article","created":{"date-parts":[[2025,3,3]],"date-time":"2025-03-03T05:16:40Z","timestamp":1740979000000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Changes in pancreatic levodopa uptake in patients with obesity and new-onset type 2 diabetes: an 18F-FDOPA PET-CT study"],"prefix":"10.3389","volume":"16","author":[{"given":"Yeongkeun","family":"Kwon","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hanseok","family":"Yoon","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jane","family":"Ha","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hyeon-seong","family":"Lee","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kisoo","family":"Pahk","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hyunwoo","family":"Kwon","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sungeun","family":"Kim","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sungsoo","family":"Park","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,3,3]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1038\/nature05482","article-title":"Mechanisms linking obesity to insulin resistance and type 2 diabetes","volume":"444","author":"Kahn","year":"2006","journal-title":"Nature"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1038\/s41580-020-00317-7","article-title":"Mechanisms controlling pancreatic islet cell function in insulin secretion","volume":"22","author":"Campbell","year":"2021","journal-title":"Nat Rev Mol Cell Biol"},{"key":"B3","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1016\/j.molmet.2019.02.008","article-title":"A role for foregut tyrosine metabolism in glucose tolerance","volume":"23","author":"Korner","year":"2019","journal-title":"Mol Metab"},{"key":"B4","doi-asserted-by":"publisher","first-page":"74","DOI":"10.1016\/j.phrs.2015.12.029","article-title":"Dopaminergic drugs in type 2 diabetes and glucose homeostasis","volume":"109","author":"Lopez Vicchi","year":"2016","journal-title":"Pharmacol Res"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1093\/ajcn\/32.9.1912","article-title":"Diurnal variations in plasma concentrations of tryptophan, tryosine, and other neutral amino acids: effect of dietary protein intake","volume":"32","author":"Fernstrom","year":"1979","journal-title":"Am J Clin Nutr"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1210\/jcem.82.11.4339","article-title":"Substantial production of dopamine in the human gastrointestinal tract","volume":"82","author":"Eisenhofer","year":"1997","journal-title":"J Clin Endocrinol Metab"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.2174\/1570159x15666170510143821","article-title":"Levodopa in parkinson's disease: current status and future developments","volume":"16","author":"Tambasco","year":"2018","journal-title":"Curr Neuropharmacol"},{"key":"B8","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1002\/ana.410080102","article-title":"Barrier mechanisms for neurotransmitter monoamines and their precursors at the blood-brain interface","volume":"8","author":"Hardebo","year":"1980","journal-title":"Ann Neurol"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1159\/000114744","article-title":"Effects of long-term L-dopa therapy on carbohydrate metabolism in patients with parkinson's disease","volume":"14","author":"Rosati","year":"1976","journal-title":"Eur Neurol"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1016\/0014-2999(67)90047-7","article-title":"On the hyperglycaemic effect of dopa and dopamine","volume":"1","author":"H\u00e5kanson","year":"1967","journal-title":"Eur J Pharmacol"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1007\/BF02171596","article-title":"Evidence for the presence of biogenic amines in pancreatic islets","volume":"19","author":"Falck","year":"1963","journal-title":"Experientia"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1007\/BF00745138","article-title":"Accumulation of dopamine in mouse pancreatic B-cells following injection of L-dopa. 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