Premium
Evidence for a contribution of paramagnetic ions to water proton spin‐lattice relaxation in normal and malignant mouse tissues
Author(s) -
Negendank William,
Corbett Thomas,
Crowley Michael,
Kellogg Christopher
Publication year - 1991
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910180204
Subject(s) - paramagnetism , chemistry , ion , proton , relaxation (psychology) , solvent , nuclear magnetic resonance , crystallography , biochemistry , biology , physics , organic chemistry , neuroscience , quantum mechanics
Paramagnetic ions complexed to proteins may lose, retain, or enhance solvent paramagnetic relaxation (SPR) relative to free solution. We measured T 1 and T 2 of three mouse cancers, their normal counterparts, and six additional tissues. Long T 1 of cancers was not caused by necrosis or by different contents of water, fat, or blood. Dissociable (TCA‐extractable) and nondissociable (ashed) Mn, Cu, and Fe were measured by AA. Cancers had less Mn, Cu, and Fe than did normal counterparts. All 12 tissues had inverse correlations between T 1 and dissociable Mn and Cu. For Mn alone to account for reduced T 1 , the extent to which SPR of the Mn‐protein complexes would be enhanced is by factors of 0.6 to 13, below the maximum observed in Mn‐enzymes. Different amounts of paramagnetic ion‐protein complexes may account for part of the differences in T 1 of water protons in different tissues, and the longer T 1 of cancer cell water may be caused in part by reduced amounts Of such complexes. © 1991 Academic Press. Inc.