Cholinesterase response in the rhabdomyosarcoma tumor and small intestine of the BALB/c mice and the radioprotective actions of exogenous ATP after lethal dose of neutron radiation.

ABSTRACT

The rhabdomyosarcoma tumors were subjected to different doses of 2.0, 3.8 and 7.0 Gy from a neutron beam facility p(66 MeV)/Be. Elevated levels of cholinesterase activity are observed in which there is a correlation between the different doses of neutron radiation and the augmentation response of this enzyme. The increase of cholinesterase activity after 7 Gy neutron irradiation as a feature of involvement in the homeostatic mechanism maintaining the proper choline/acetylcholine ratio in the cell is also observed at 1 and 24 h in both tissues, rhabdomyosarcoma and small intestine. The activity of the enzyme after neutron irradiation with prior administration of ATP showed smaller increases when compared with increases observed after neutron irradiation alone. Moreover in the present work the protective mechanism of ATP in the response of cholinesterase activity is marked differential between both, normal and tumoral tissue and correlated inversely with the administered of the following concentrations of exogenous ATP (8, 25, 80, 250, and 700 mg/kg body weight) prior to exposure to 7 Gy neutron radiation. These results reflect the radioprotective ability of exogenous ATP to exert a number of metabolic adaptations as a defense mechanism in which the cell exposed to neutron radiation could remain viable because the injury is potentially repairable.