Effect of Androgen on Normal Biodistribution of [18F]-2'-Fluoro-5-methyl-1-beta-D-arabinofuranosyluracil (18F-FMAU) in Athymic Non-tumor-bearing Male Mice.
We assessed the association between the presence and absence of androgen on the normal biodistribution of the positron emission tomography (PET) cellular proliferation imaging biomarker, [18F]-2'-Fluoro-5-methyl-1-beta-D-arabinofuranosyluracil (18F-FMAU), in mice.



Non-castrated (n=4) and castrated (n=4) athymic non-tumor-bearing male mice served as models for presence and absence, respectively, of androgen. MicroPET-CT scans were performed 1 h following tail vein administration of 200 uCi of18F-FMAU. Imaging was performed at baseline and then at 7-day intervals longitudinally for 35 days only in castrated mice following subcutaneous introduction of a 12.5 mg, 21-day release, dihydrotestosterone pellet. Mean standardized uptake values (SUVmean) were obtained for liver, heart, and muscle. Several two-group comparisons of average of SUVmeanwere performed.



Pre-pellet baseline average SUVmean(±s.d.) values in castrated mice were significantly lower than baseline non-castrated values, increased on day 15 and reached peak values on day 28, at which time they were significantly higher than corresponding baseline levels in both non-castrated and pre-pellet castrated mice. The peak values decreased significantly following dihydrotestosterone withdrawal.



There is a significant modulatory effect of androgen on normal18F-FMAU uptake levels in mice liver, heart and muscle tissues.
Department of Radiology, USC Molecular Imaging Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, U.S.A. jadvar@med.usc.edu.
Hossein
H
Jadvar
Department of Radiology, USC Molecular Imaging Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, U.S.A.
Ryan
R
Park
Department of Radiology, USC Molecular Imaging Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, U.S.A.
Li-Peng
LP
Yap
Department of Radiology, USC Molecular Imaging Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, U.S.A.
Kai
K
Chen
Department of Radiology, USC Molecular Imaging Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, U.S.A.
Lindsey
L
Hughes
Department of Radiology, USC Molecular Imaging Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, U.S.A.
Peter
P
Conti
D000728:Androgens / Q000378:metabolism*; D000818:Animals; D001086:Arabinofuranosyluracil / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D003692:Delayed-Action Preparations; D013196:Dihydrotestosterone / Q000008:administration & dosage; D005462:Fluorine Radioisotopes / Q000032:analysis; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009919:Orchiectomy; D000072078:Positron Emission Tomography Computed Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D014018:Tissue Distribution
D000728:Androgens; D003692:Delayed-Action Preparations; D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D013196:Dihydrotestosterone; D001086:Arabinofuranosyluracil; C034935:clevudine
Androgen; FMAU; PET; prostate