1H NMR spectroscopy: an approach to evaluation of diseased skin in vivo.

1H nuclear magnetic resonance (NMR) spectroscopy was tested for its applicability in evaluating diseased skin. In order to explore potential spectral markers characteristic of diseased tissue, perchloric acid (PCA) extracts of psoriasis and malignant melanoma tissues were compared with normal skin, and changes in melanoma after heat treatment were monitored. In psoriatic plaque extract, the spectral peak intensity ratios of Glu: Ser, creatine: Gly, and taurine: Ala were approximately three-fold compared with symptom-free or normal skin, whereas Val: Leu/Ile was one-half the normal skin ratio. In melanoma extracts, the phosphorylcholine (PC)/glycerophosphorylcholine (GPC): Ala, Glu: Ser, and lactate: Ala ratios were five-, three-, and two-fold higher, respectively, than normal skin and the Val: Leu/Ile ratio was two-thirds of normal skin. With heat treatment, PC/GPC: Ala and Glu: Ser ratios decreased, whereas lactate: Ala and Val: Leu/Ile ratios increased three-fold and one-third, respectively. Results indicate that 1H NMR spectroscopy is a sufficiently sensitive technique to distinguish normal from diseased skin. The main attraction of this technique lies in the possibility of non-invasive study of various skin diseases, malignant transformation of benign tumors, and responses to treatment. Several methodologic problems remain to be resolved before a meaningful interpretation of in vivo observations becomes feasible. Correlation of in vivo and in vitro findings is an essential step toward this goal.