DETECTION OF ANISOTROPY IN CARTILAGE USING H-2 DOUBLE-QUANTUM-FILTERED NMR-SPECTROSCOPY

Double-quantum-filtered (DQF) NMR spectroscopy of I = 1 spin systems i s a diagnostic tool for the detection of anisotropy in macroscopically disordered systems. For deuterium, this method reveals the presence o f a residual quadrupolar interaction for D2O in bovine nasal cartilage . This tissue is not macroscopically ordered and the quadrupolar split ting is not resolved. Fitting the calculated spectral lineshapes to th e experimental results was possible only when a distribution of the re sidual quadrupolar interaction, omega(q), was assumed. The series of D QF lineshapes obtained for different creation times in the DQF experim ent could be fitted using a single set of three parameters: the averag e residual quadrupolar interaction ($) over bar omega(q)/2 pi = 110 Hz , its standard deviation Delta omega(q)/2 pi = 73 Hz, and the transver se relaxation rate of 63 s(-1). Separate deuterium DQF measurements fo r the constituents of the cartilage, collagen, and chondroitin sulfate indicated that the DQF spectra of cartilage are the result of anisotr opic motion of D2O due to binding to the fibrous collagen in the tissu e. (C) 1995 Academic Press, Inc.