2-aminoethylphosphonic acid: biodistribution of a naturally occurring phosphonate after labelling with technetium-99m.
Phosphonic acid derivatives (P-C-P bond) are thought to be devoid of a mammalian synthetic pathway. Nevertheless, a natural phosphonate derivative, 2-aminoethylphosphonic acid (2-AEP), has been detected in animal and human tissue. After labelling with 99Tcm, biodistribution studies were performed in normal and tumour-bearing rats. A scintigraphic rabbit investigation was also completed. When expressed as percent injected dose per gram, the lung, liver, kidney and bone concentrated > 1% of the 99Tcm-2-AEP at 5 min. By 6 h, the liver, bone, marrow and kidney dominated. The 2 h rabbit scintigraphic image coincided with the rat data. Tumour-to-organ ratios showed values intermediate with those obtained with 99Tcm-diphosphonate and 99Tcm-pertechnetate. 99Tcm-2-AEP may show promise as a soft tumour scintigraphic agent because of its unique structure and low gastrointestinal uptake, provided the relatively short t1/2p of 99Tcm proves to be suitable.
Castronovo
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FP
Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA.
Kopiwoda
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S
Peterson
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M
D000615:Aminoethylphosphonic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics* / Q000627:therapeutic use; D000818:Animals; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism; D005910:Glioma / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D008297:Male; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics* / Q000627:therapeutic use; D011817:Rabbits; D011877:Radionuclide Imaging; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014018:Tissue Distribution
D015609:Organotechnetium Compounds; C105583:technetium Tc 99m 2-aminoethylphosphonic acid; D000615:Aminoethylphosphonic Acid