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Annals of Nuclear Medicine

, Volume 22, Issue 4, pp 301–307 | Cite as

Evaluation of brain and whole-body pharmacokinetics of 11C-labeled diphenylhydantoin in rats by means of planar positron imaging system

  • Yukinori Hasegawa
  • Yasukazu Kanai
  • Shinji Hasegawa
  • Takashi Okamoto
  • Tamiko Matsui
  • Eku Shimosegawa
  • Yoshihisa Kurachi
  • Jun HatazawaEmail author
Original Article

Abstract

Objective

A planar positron imaging system (PPIS) enables whole-body dynamic imaging of radiopharmaceuticals labeled with positron-emitting nuclides. We evaluated the difference in the brain and whole-body pharmacokinetics of 11C-diphenylhydantoin (11C-DPH) between intravenous and duodenal administration in rats.

Methods

Male Wistar rats (8 weeks old, mean body weight 250 g) were examined under anesthesia. A tracer amount of 11C-DPH (2 μg or less; about 5 MBq) was injected into the tail vein (n = 3) or duodenum (n = 3). Immediately following the administration, PPIS scans were obtained for 20 min. Regions of interest (ROIs) were set on the brain, heart, liver, intestinal field, and urinary bladder, identified on the integrated images. The relative uptake value (RUV, %) was calculated as the regional count divided by the whole-body count multiplied by 100. Sequential changes in the RUV for each ROI were analyzed for the brain and other organs.

Results

Following intravenous injection of 11C-DPH, the RUV in the brain was 1.59 ± 0.07%, 1.53 ± 0.09%, 1.40 ± 0.09%, and 1.38 ± 0.08% at 5 min, 10 min, 15 min, and 20 min after the injection, respectively. After duodenal administration, the corresponding values were 0.54 ± 0.16%, 1.01 ± 0.12%, 1.43 ± 0.24%, and 1.52 ± 0.06%, respectively. The 11C-DPH distribution was significantly lower at 5 min and 10 min following duodenal administration than after intravenous injection (P < 0.01). Radioactivity in the urinary bladder was identified by 20 min after both intravenous injection and duodenal administration.

Conclusions

The present study demonstrated a difference in the brain distribution of 11C-DPH between intravenous and duodenal administration in rats. Use of the PPIS is feasible for the evaluation of the pharmacokinetics in both the target organ and the whole body in small animals.

Keywords

PPIS 11C-DPH Pharmacokinetics 

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Copyright information

© The Japanese Society of Nuclear Medicine 2008

Authors and Affiliations

  • Yukinori Hasegawa
    • 1
  • Yasukazu Kanai
    • 1
  • Shinji Hasegawa
    • 1
  • Takashi Okamoto
    • 2
  • Tamiko Matsui
    • 3
  • Eku Shimosegawa
    • 1
  • Yoshihisa Kurachi
    • 4
  • Jun Hatazawa
    • 1
    Email author
  1. 1.Department of Nuclear Medicine and Tracer KineticsOsaka University Graduate School of MedicineOsakaJapan
  2. 2.Hamamatsu Photonics K.K.HamamatsuJapan
  3. 3.Nihon Medi-Physics Co. Ltd.NishinomiyaJapan
  4. 4.Department of PharmacologyOsaka University Graduate School of MedicineOsakaJapan

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