Nuclear magnetic resonance study of muscle water protons in muscular dystrophy of chickens.

Using the pulsed nuclear magnetic resonance (NMR) spectroscopy, the spin-lattice (T1) and the spin-spin (T2) relaxations times of water protons from samples of pectoralis major muscles of normal (line 412) and homozygous dystrophic (line 413) chickens were measured. Both the T1 and T2 were significantly increased (P less than 0.05) in the dystrophic muscles. The mean values of the relaxation times are given +/- S.D. The T1 values were 654 +/- 22 msec in normal and 692 +/- 41 msec in dystrophic muscles. The T2 values for normal and dystrophic muscles were 39 +/- 4 msec and 52 +/- 7 msec, respectively. Although the water content of dystrophic muscles (78.9 +/- 0.6%) determined by gravimetric methods was significantly higher than normal muscles (74.9 +/- 1.1%), this difference in tissue hydration could not explain quantitatively the increase of T1 and T2 values in the dystrophic muscles. The results of the measurements of the relaxation times seem to suggest that there are changes in the composition and/or conformational state of the proteins.