RT Journal Article
SR Electronic
T1 PET Imaging of the Gastrointestinal Absorption of Orally Administered Drugs in Conscious and Anesthetized Rats
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 249
OP 256
DO 10.2967/jnumed.110.081539
VO 52
IS 2
A1 Yamashita, Shinji
A1 Takashima, Tadayuki
A1 Kataoka, Makoto
A1 Oh, Hiroyuki
A1 Sakuma, Shinji
A1 Takahashi, Masayuki
A1 Suzuki, Norio
A1 Hayashinaka, Emi
A1 Wada, Yasuhiro
A1 Cui, Yilong
A1 Watanabe, Yasuyoshi
YR 2011
UL http://jnm.snmjournals.org/content/52/2/249.abstract
AB This study assessed the process of gastrointestinal drug absorption in vivo using PET. Methods: 18F-FDG was used as a model probe and was orally administered to rats as a solution. PET scans were obtained of the whole body and abdominal region under conscious and anesthetized conditions. Blood samples were routinely taken from the femoral vein during scanning. The rate of gastric emptying and intestinal absorption of 18F-FDG was estimated from the time profiles of radioactivity in the stomach and small intestine. In addition, nonradiolabeled 2-fluoro-2-deoxy-d-glucose (2-FDG) was used in an intestinal closed-loop experiment to compare the intestinal permeability of 2-FDG with that of d-glucose. Results: In conscious rats, gastrointestinal absorption of 18F-FDG was rate-limited by the process of intestinal membrane permeation, because the permeability of 2-FDG through the intestinal membrane was low compared with that of d-glucose. In anesthetized rats, the gastric emptying rate of 18F-FDG decreased dramatically whereas the intestinal absorption rate constant was not significantly different from that in conscious rats. As a result, the rate-limiting step of gastrointestinal absorption of 18F-FDG was shifted to the gastric emptying process by anesthesia. Conclusion: PET technology is a powerful tool for in vivo analysis of the gastrointestinal absorption of orally administered drugs.