Observation of reorientationally hindered water in biological tissue using triple quantum filtered 17O-NMR.

Water dynamics in aqueous biopolymer solutions often display a two-phase character, resembling water-water and water-protein interactions. Rotationally hindered water molecules in crowded protein environments display triple exponential magnetic relaxation out of the extreme narrowing limit. Because water-protein interactions retard the water dynamics, H2O(17) magnetization passes through a NMR multiple quantum coherence filter, allowing the visualization of reorientationally hindered water without the disturbing resonance of the bulk. In vitro experiments performed on selected biological materials (lens, vitreous body and serum albumin solutions) clearly demonstrate the potential of this technique.