Dynamic electron spin resonance (ESR) imaging of the distribution of spin labeled dextran in a mouse.
The nitroxide group 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was covalently bound to a dextran via an N-acetamido linkage to produce a novel spin probe, TEMPO-dextran (TEMPO-DX), which circulates for long time periods in an animal without metabolic degradation. TEMPO-DX was stable in mice, while small TEMPO analogs quickly disappeared after administration. Since dextran was reduced somewhat in size during synthesis, the resultant spin-labeled dextran could be excreted through the kidney. A strong L-band electron spin resonance signal was obtained shortly after intravenous administration of TEMPO-DX into the tail vein of a mouse, from which three-dimensional images of specific organs were calculated. The signal was found to persist for well over 1 h.
Kazama
S
S
School of Pharmaceutical Sciences, University of Shizuoka, Japan.
Takashige
G
G
Yoshioka
H
H
Tanizawa
H
H
Ogata
T
T
Koscielniak
J
J
Berliner
L J
LJ
D000818:Animals; D003497:Cyclic N-Oxides / Q000493:pharmacokinetics*; D003911:Dextrans / Q000493:pharmacokinetics*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D007668:Kidney / Q000378:metabolism; D008297:Male; D051379:Mice; D013113:Spin Labels; D001743:Urinary Bladder / Q000378:metabolism
D003497:Cyclic N-Oxides; D003911:Dextrans; D013113:Spin Labels; C003959:TEMPO