Spin Echo Studies on Cellular Water

HIGH resolution nuclear magnetic resonance (NMR) studies on rat skeletal muscle have recently shown that cellular water produces an absorption line almost ten times as broad as the line width of pure water 1 . This suggests that these water molecules are at least partly bounded such that the proton correlation time is increased. Similar observations have also been made for deuterated water in skeletal muscle 2 and for H 2 O in other tissues 3–5 . Our results further substantiate the notion that ordered water exists in biological tissue and rules out several criticisms of this interpretation.