Recent NMR spectroscopy developments, such as high-resolution magic angle spinning (HRMAS) probes and correlation-enhanced 2D sequences, now allow improved investigations of
phospholipid (Plp) metabolism. Using these modalities we previously demonstrated that a mouse-bearing
melanoma tumor responded to chloroethyl nitrosourea (
CENU) treatment in vivo by altering its Plp metabolism. The aims of the present study were to investigate whether HRMAS
proton total correlation spectroscopy (TOCSY) could be used as a quantitative technique to probe Plp metabolism, and to determine the Plp metabolism response of cultured
B16 melanoma cells to
CENU treatment in vitro. The exploited TOCSY signals of Plp derivatives arose from scalar coupling among the
protons of neighbor methylene groups within base headgroups (
choline and
ethanolamine). For strongly expressed Plp derivatives, TOCSY signals were compared to saturation recovery signals and demonstrated a linear relationship. HRMAS
proton TOCSY was thus used to provide concentrations of Plp derivatives during long-term follow-up of
CENU-treated cell cultures. Strong Plp metabolism alteration was observed in treated cultured cells in vitro involving a down-regulation of
phosphocholine, and a dramatic and irreversible increase of
phosphoethanolamine. These findings are discussed in relation to previous in vivo data, and to Plp metabolism enzymatic involvement.