MXT mammary tumor treated by low dose chemotherapy. A 31P-NMR and 1H-MRI study.

The effects induced by a low dose cyclophosphamide treatment (CPA) along with an attempt of estradiol-17-beta (E2) cell recruitment, on the bioenergetics and the phosphomonoesters/phosphodiesters (PME/PDE) ratio in the transplantable MXT mouse mammary tumor have been studied by 31P-NMR spectroscopy in vivo. Our results show that neither ovariectomy (OO) nor the additional low dose E2 + CPA treatment significantly decreased tumor growth, whilst E2 + CPA treatment induced significant modifications compared to values recorded in tumors grafted on intact or ovariectomized animals, of all peak height ratios but PME/PDE, which further remained at a constant value during tumor growth.