Chemiluminescence from an erythrocyte folic acid oxidase from normal individuals and from cancer patients.

Folic acid oxidase from erythrocytes oxidatively cleaves folic acid at the C-9-N-10 bond to yield pterin-6-aldehyde and p-aminobenzoyl glutamic acid, with the concomitant generation of singlet oxygen. The emission from singlet oxygen is proportional to the enzyme activity. DABCO was used as a singlet oxygen emission enhancer to increase the sensitivity of the measurement. In general, pregnant women show high enzymatic activity, but the emission is strongly quenched by DABCO. This is contrary to normal and cancer cases in which an increase in the emission was observed. This effect is larger in cancer cases. These results are presented as a potential method for detecting physiological and pathological human conditions.

Electronically excited species in the spontaneous chemiluminescence of urine and its uses in the detection of pathological conditions.

A relatively simple procedure for the measurement of urinary chemiluminescence is described and some of the variables affecting such measurements are examined. Normal urinary chemiluminescence is due to lipoperoxidation, presumably through the Haber-Weiss reaction, generating singlet oxygen as emitter. It was found that urinary chemiluminescence was higher in normal smokers than in normal non-smokers and very low in cancer patients. Oral distribution of ascorbic acid reduced urinary chemiluminescence of both normal smokers and non-smokers. Presumably, the spontaneous chemiluminescence in the urine could serve as a cancer marker.