抄録
Water in skeletal muscle is inhomogeneous from various aspects. This is the source of the power of MRI to distinguish various tissues of various patho-physiological states. The states of water would naturally affect biochemical reactions taking place in vivo, and therefore significantly affect our sound understanding of living organisms. We have been studied the osmotic activity of myowater in intact and skinned skeletal muscle, whose liquid-crystalline structure is advantageous in defining water states in the tissues. Our results revealed that water in skeletal muscle tissue can be grouped into four characteristic components. In the present study, considering the water vapor pressure in equilibrium with each water components, we found that each water components can be characterized by the activity profile of water molecules which is one of the basic physicochemical characteristics of molecules. To extend our fining in skeletal muscle to general biological tissues, we tried to find relationships between water components and water activity in several tissues of characteristic histological features (such as brain and testis). The results suggested an apparent discrepancy form the general view of water states developed by ordinary radiologists to evaluate MRI. [J Physiol Sci. 2008;58 Suppl:S65]
