Nuclear magnetic resonance relaxation time and self‐diffusion coefficient measurements of water in frog ovarian eggs (Rana pipiens)

Abstract

AbstractSelf‐diffusion coefficient measurements of water in untreated ovarian eggs of Rana pipiens using nuclear magnetic resonance indicate that cytoplasmic water has reduced translational mobility compared with pure water. Using a simple two‐state model, we find that ∼67% is “relatively immobile.” Consideration of the nuclear magnetic resonance spin‐lattice and spin‐spin relaxation times indicates that the decreased mobility can largely be ascribed to hydration. Our value for the self‐diffusion coefficient (6.8 × 10−6 cm2/sec) is lower than those reported by other investigators using isotopic water exchange techniques on frog eggs chemically treated to remove the membrane. However, the results reported here are in agreement with unpublished data on untreated frog eggs implying that chemical treatment has modified the cytoplasm in some manner.