MEMRI and tumors: a method for the evaluation of the contribution of Mn(II) ions in the extracellular compartment.
NMR Biomed
; 28(9): 1104-10, 2015 Sep.
Article
em En
| MEDLINE
| ID: mdl-26174622
ABSTRACT
The purpose of the work was to set-up a simple method to evaluate the contribution of Mn(2+) ions in the intra- and extracellular tumor compartments in a MEMRI experiment. This task has been tackled by "silencing" the relaxation enhancement arising from Mn(2+) ions in the extracellular space. In vitro relaxometric measurements allowed assessment of the sequestering activity of DO2A (1,4,7,10-tetraazacyclododecane-1,7-diacetic acid) towards Mn(2+) ions, as the addition of Ca-DO2A to a solution of MnCl2 causes a drop of relaxivity upon the formation of the highly stable and low-relaxivity Mn-DO2A. It has been proved that the sequestering ability of DO2A towards Mn(2+) ions is also fully effective in the presence of serum albumin. Moreover, it has been shown that Mn-DO2A does not enter cell membranes, nor does the presence of Ca-DO2A in the extracellular space prompt migration of Mn ions from the intracellular compartment. On this basis the in vivo, instantaneous, drop in SE% (percent signal enhancement) in T1 -weighted images is taken as evidence of the sequestration of extracellular Mn(2+) ions upon addition of Ca-DO2A. By applying the method to B16F10 tumor bearing mice, T1 decrease is readily detected in the tumor region, whereas a negligible change in SE% is observed in kidneys, liver and muscle. The relaxometric MRI results have been validated by ICP-MS measurements.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Melanoma Experimental
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Imageamento por Ressonância Magnética
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Manganês
Limite:
Animals
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Female
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Humans
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article