Studies on cervical intraepithelial neoplasia: the level of octadeca-9,11-dienoic acid and measurement of free radical content by electron spin resonance spectroscopy.

The efficacy of electron spin resonance spectroscopy (a technique that measures free radicals) in detecting cervical intraepithelial neoplasia was evaluated in 68 women. In addition, electron spin resonance spectroscopic data were correlated with the phospholipid-esterified octadeca-9,11-dienoic acid (18:2(9,11]/octadeca-9,12-dienoic acid (18:2(9,12] molar ratio, a suggested marker of free radical damage to linoleic acid. Incubation of cervical epithelial cells with the spin-trap N-tert-butyl-alpha-phenylnitrone and subsequent examination by electron spin resonance spectroscopy gave signals from a nitroxide radical, which has been tentatively assigned to an adduct from either a carbon-centered lipid radical or a lipid alkoxyl radical; no significant differences in either the type of radical detected or the intensity of the signals was found between patients with cervical intraepithelial neoplasia and normal control subjects. There was no significant correlation between the intensity of the electron spin resonance signal and the phospholipid-esterified 18:2(9,11)/18:2(9,12) molar ratio. This finding provides no support for the classification of 18:2(9,11) as a "free radical product."