SPIN-LATTICE RELAXATION-TIMES OF WATER IN POLARIZED AND DEPOLARIZED RABBIT VAGUS NERVES

Spin-lattice relaxation times (T-1) of intracellular water of the nonm yelinated fibers of rabbit cervical vagus nerve were measured using a paramagnetic shift reagent, s-FDF. Spin-lattice relaxation decay curve s were composed of the fast (T-1,T-F) and slow (T-1,T-S) relaxation co mponents:. The mean values of T-1,T-F and T-1,T-S in the polarized ner ve fibers at 25 degrees C were 0.12 +/- 0.04 and 0.61 +/- 0.13 sec., r espectively, and their fractions were 0.71 +/- 0.07 and 0.29 +/- 0.07, respectively (n = 21). On the other hand, those values in the depolar ized nerve fibers were 0.16 +/- 0.01 sec., 0.77 +/- 0.17 sec., 0.77 +/ - 0.10 and 0.23 +/- 0.10, respectively (n = 15). (T) over bar(1,F) and (T) over bar(1,S) for the depolarized nerve fibers were significantly elongated (P < 0.01). (C) 1995 Academic Press, Inc.