Self diffusion of water in frog muscle.

Self diffusion of cell water has been measured at diffusion times ranging form 0.3 ms to 2.4 s for three muscle types of Rana pipiens, using various magnetic field gradient nuclear magnetic resonance methods. Intracellular diffusion coefficients and membrane permeabilities are calculated with the aid of previous theoretical results for regularly spaced permeable planar barriers. The intracellular diffusion coefficient is 1.6 x 10-5 cm2/s, in approximate agreement with other literature values for skeletal muscles. The outer membrane permeabilities are estimated at 0.01 cm/s for two of the muscle types, and much higher for the other one.