TY - JOUR
T1 - 11C-methionine uptake to the pancreas and its secretion
T2 - A positron emission tomography study in humans
AU - Takasu, Atsuko
AU - Shimosegawa, Tooru
AU - Shimosegawa, Eku
AU - Hatazawa, Jun
AU - Kimura, Kenji
AU - Fujita, Motokazu
AU - Koizumi, Masaru
AU - Kanno, Iwao
AU - Toyota, Takayoshi
PY - 1999/5
Y1 - 1999/5
N2 - The aim of this study was to investigate the uptake of [11C-methyl]- L-methionine (11C-methionine) in the human pancreas by analyzing dynamic positron emission tomography (PET) images and the duodenal aspirate. A double-lumen tube was inserted in the duodenum and dynamic PET was performed in seven healthy volunteers for 110 min after intravenous (i.v.) injection of 11C-methionine during the continuous i.v. administration of secretin (125 ng/kg/h) and cerulein (30 ng/kg/h). For the calculation of the radioactivity in the pancreas, the regions of interest were set on the PET images. Radioactivity was measured in 10-min fractions of duodenal juice. After i.v. injection, 11C-methionine accumulated in the pancreas within a few minutes, and the radioactivity plateaued during the study. The radiolabeled proteins in the duodenal juice increased linearly 30 min after 11C-methionine injection, but the relative rates of radioactivity in the protein precipitate to the total count in the duodenal juice were 44-48%. From these findings, it was concluded that 11C-methionine accumulation in the pancreas is very rapid after the i.v. administration, and only a part of methionine uptake to the pancreas is incorporated into secretory proteins. The pancreatic 11C- methionine uptake detected by PET may represent a new aspect of exocrine pancreatic function that has not been expressed by the conventional intubation method.
AB - The aim of this study was to investigate the uptake of [11C-methyl]- L-methionine (11C-methionine) in the human pancreas by analyzing dynamic positron emission tomography (PET) images and the duodenal aspirate. A double-lumen tube was inserted in the duodenum and dynamic PET was performed in seven healthy volunteers for 110 min after intravenous (i.v.) injection of 11C-methionine during the continuous i.v. administration of secretin (125 ng/kg/h) and cerulein (30 ng/kg/h). For the calculation of the radioactivity in the pancreas, the regions of interest were set on the PET images. Radioactivity was measured in 10-min fractions of duodenal juice. After i.v. injection, 11C-methionine accumulated in the pancreas within a few minutes, and the radioactivity plateaued during the study. The radiolabeled proteins in the duodenal juice increased linearly 30 min after 11C-methionine injection, but the relative rates of radioactivity in the protein precipitate to the total count in the duodenal juice were 44-48%. From these findings, it was concluded that 11C-methionine accumulation in the pancreas is very rapid after the i.v. administration, and only a part of methionine uptake to the pancreas is incorporated into secretory proteins. The pancreatic 11C- methionine uptake detected by PET may represent a new aspect of exocrine pancreatic function that has not been expressed by the conventional intubation method.
KW - Amino acid uptake
KW - C-Methionine
KW - Exocrine pancreas
KW - Human
KW - Positron emission tomography (PET)
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U2 - 10.1097/00006676-199905000-00010
DO - 10.1097/00006676-199905000-00010
M3 - Article
C2 - 10231845
AN - SCOPUS:0032587534
VL - 18
SP - 392
EP - 398
JO - Pancreas
JF - Pancreas
SN - 0885-3177
IS - 4
ER -