Ferritin-induced relaxation in tissues: an in vitro study.
OBJECTIVE
To study in vitro the proton relaxation induced in tissues by ferritin, the iron-storing protein of mammals.


METHODS
Nuclear magnetic relaxation dispersion (NMRD) profiles of liver and spleen from control and iron-overloaded mice are compared with NMRD profiles of ferritin and Fercayl-a ferritin-like akaganeite particle-in aqueous solutions or in 1% agarose gel.


RESULTS
The relaxation of water protons induced by ferritin and Fercayl in 1% agarose gel is comparable with the relaxation of aqueous solutions of the same compounds, but slower than the relaxation of liver and spleen. The gel is not a good model of tissues containing ferritin. The longitudinal NMRD profiles of control and iron-overloaded liver and spleen are almost identical: ferritin accumulation has only a slight effect on longitudinal relaxation. The transverse NMRD profiles of liver and spleen tissues are linear, but the slope of the linear regression is larger for iron-loaded organs than for control ones, which is a consequence of a higher ferritin concentration in the former. However, the correlation between the slope of the transverse NMRD profiles and the iron concentration is not very good, probably because transverse relaxation is modified by the clustering of ferritin in cells.


CONCLUSIONS
It could be difficult to develop a general technique for the accurate quantification of ferritin-bound iron by nuclear magnetic resonance or magnetic resonance imaging.
Gossuin
Yves
Y
Biological Physics Department, Faculty of Medicine and Pharmacy, University of Mons-Hainaut, Mons, Belgium. yves.gossuin@umh.ac.be
Burtea
Carmen
C
Monseux
Anne
A
Toubeau
Gérard
G
Roch
Alain
A
Muller
Robert N
RN
Gillis
Pierre
P
D000818:Animals; D005290:Ferric Compounds / Q000494:pharmacology*; D005293:Ferritins / Q000378:metabolism*; D005782:Gels; D006736:Horses; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012685:Sepharose; D012996:Solutions; D013154:Spleen / Q000378:metabolism*
D005290:Ferric Compounds; D005782:Gels; D012996:Solutions; C473845:akaganeite; D005293:Ferritins; D012685:Sepharose