C-13 NMR-SPECTROSCOPY OF LIPIDS - A SIMPLE METHOD FOR ABSOLUTE QUANTITATION

There is both epidemiological and experimental evidence of the effect of fatty acid molecular structure,particularly the degree of saturatio n in fatty acyl chains, on the growth and regulation of certain tumour s. In vivo carbon nuclear magnetic resonance spectroscopy has previous ly been shown to offer a non invasive technique for the evaluation of proportions of monounsaturated, polyunsaturated and saturated fatty ac ids in human adipose tissue. We present a simple method, which uses bo th endogenous water and fat as reference, to quantify in molar terms t hese lipid sub-categories for tissues other than pure fat. This could provide additional information in the debate on the protective effect in cancer of high polyunsaturated fatty acid (PUFA) diet. The method w as validated by characterization of a lipid emulsion of known composit ion in various experimental set-ups and was applied to measure the lip id composition of the calves of two volunteers. Limitations and perspe ctives of the method are discussed.