DISCRIMINATION BETWEEN THE DIFFERENT COMPARTMENTS IN SCIATIC-NERVE BYH-2 DOUBLE-QUANTUM-FILTERED NMR

The H-2 double-quantum-filtered (DQF) NMR spectrum of isolated rat sci atic nerve, equilibrated with deuterated saline, is composed of three quadrupolar-split water signals. On the basis of the time course of th eir shift by Co-EDTA(2-) and CoCl2,, the signals with quadrupolar spli ttings of about 120, 470, and 9 Hz were assigned to water in the epine urium, endoneurium, and intraaxonal compartments, respectively. The si gnal of the bulk water, which experiences isotropic motion, was elimin ated by the DQF pulse sequence, As the maximum Intensities of the wate r signals in the three anisotropic compartments occur at different cre ation times, in the DQF pulse sequence, it is possible to resolve the signals and measure their properties, such as relaxation times, indepe ndently, without perturbing the system with shift reagents. (C) 1997 A cademic Press.