WR-2721 protection of pneumonitis and fibrosis in mouse lung after single doses of x rays

Journal Article · Wed Feb 01 04:00:00 EST 1984 · Int. J. Radiat. Oncol., Biol. Phys.; (United States)

DOI:https://doi.org/10.1016/0360-3016(84)90010-5· OSTI ID:7133157

Travis, E L; Parkins, C S; Holmes, S J; Down, J D; Fowler, J F

The radioprotective effect of WR-2721 has been studied in mouse lung after single doses of radiation. Using the breathing rate assay and lethality, radioprotection was assessed at monthly intervals between 3 and 18 months after irradiation during both pneumonitis and chronic fibrosis. The degree of radioprotection was greater for fibrosis than for pneumonitis using both assays. In replicate experiments, dose modifying factors (DMF's) ranging from 1.2 to 1.4 were obtained for pneumonitis and 1.5 and 1.6 for fibrosis. The differences in DMF's for the two phases of lung damage were significant. A difference in the time course of expression of damage was seen in both the breathing rate and lethality assays between mice irradiated with and without WR-2721: the damage ended sooner in the drug-treated mice. This difference is best explained by protection of all damage after 5 months by WR-2721. No evidence of drug toxicty was found. It was concluded that WR-2721 protects against chronic lung fibrosis caused by radiation at least as well as against the earlier appearing pneumonitis after single doses of radiation. Thus, if WR-2721 is dose modifying and if late tissue complications are dose limiting in clinical radiotherapy, then a therapeutic benefit would be obtained by the use of this drug in clinical radiotherapy, provided that the radioprotection of tumors did not exceed a factor of 1.5-1.6.

• Research Organization: Mount Vernon Hospital, Northwood, England
• OSTI ID: 7133157
• Journal Information: Int. J. Radiat. Oncol., Biol. Phys.; (United States), Journal Name: Int. J. Radiat. Oncol., Biol. Phys.; (United States) Vol. 10:2; ISSN IOBPD
• Country of Publication: United States
• Language: English

Related Subjects

550900 -- Pathology
560152* -- Radiation Effects on Animals-- Animals
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGY
BODY
ELECTROMAGNETIC RADIATION
FIBROSIS
IONIZING RADIATIONS
LUNGS
MAMMALS
MICE
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PATHOLOGICAL CHANGES
PNEUMONITIS
RADIATIONS
RADIOBIOLOGY
RADIOINDUCTION
RADIOSENSITIVITY EFFECTS
RESPIRATORY SYSTEM
RODENTS
THIOLS
VERTEBRATES
X RADIATION