31P magnetic resonance of intact endocrine tissue: adrenal glands of dogs.

Intact dog adrenal glands were examined for their phosphate profiles in the 31P nuclear magnetic resonance spectrometer at 36.43 MHz at 31 degrees, and the resultant spectra were compared to those obtained from perchloric acid extracts of the same endocrine tissue. The adrenal gland presents a unique organ for whole tissue spectroscopy in that its phosphate profile shows a number of features which have not been previously observed in similar phosphate profiles obtained from other intact tissue preparations. A number of prominant resonances are observed in the intact adrenal gland which arise from phosphorus-containing substances that are not extractable with perchloric acid. The 31P shifts of these resonances indicate that they may arise from phosphorylated proteins and membrane phospholipids.