IN-VIVO AND IN-VITRO STUDIES OF CYCLOPHOSPHAMIDE CHEMOTHERAPY IN A MOUSE MAMMARY-CARCINOMA BY P-31 NMR-SPECTROSCOPY

The effect of cyclophosphamide on the metabolic profile of a mammary c arcinoma implanted on the foot of mouse was studied by P-31 NMR spectr oscopy both in vivo and in perchloric acid extracts, The ratio nucleot ide triphosphate:Pi was significantly elevated in cyclophosphamide tre ated tumours relative to untreated tumours after 96 h in vivo (p<0.05) , Phosphocreatine:P-i was similarly elevated from 48 to 168 h (p<0.01) , Resolution of the phosphomonoester peak into two distinct resonances allowed us to estimate the ratio of PME' to phosphocholine (PC), wher e PME' is a composite peak consisting, in part, of phosphoethanolamine (PE), PME':PC was found to be significantly higher in treated animals relative to control animals in vivo (p<0.01 from 48 to 168 h), Perchl oric acid extract spectra suggest that the increase in PME':PC was in part due to a decrease in PC concentration and also due to an increase in a previously unidentified resonance which was coresonant with PE, Extract data show that there was a significant increase in the concent ration of the phosphodiesters, glycerophosphocholine (p<0.01) and glyc erophosphoethanolamine (p<0.05) in treated relative to control tumours , The changes in the phosphomonoester resonances are qualitatively sim ilar to previously described changes following radiation and suggest t hat they may be a marker of cell kill or lack of cell growth after ant ineoplastic therapy.