Discrimination between the Different Compartments in Sciatic Nerve by ²H Double-Quantum-Filtered NMR

The ²H double-quantum-filtered (DQF) NMR spectrum of isolated rat sciatic nerve, equilibrated with deuterated saline, is composed of three quadrupolar-split water signals. On the basis of the time course of their shift by Co-EDTA^2- and CoCl₂, the signals with quadrupolar splittings of about 120, 470, and 9 Hz were assigned to water in the epineurium, endoneurium, and intraaxonal compartments, respectively. The signal of the bulk water, which experiences isotropic motion, was eliminated by the DQF pulse sequence. As the maximum intensities of the water signals in the three anisotropic compartments occur at different creation times, in the DQF pulse sequence, it is possible to resolve the signals and measure their properties, such as relaxation times, independently, without perturbing the system with shift reagents.