Radiation response of the rat cervical spinal cord after irradiation at different ages: Tolerance, latency and pathology

Journal Article · Sat Apr 30 00:00:00 EDT 1994 · International Journal of Radiation Oncology, Biology and Physics; (United States)

DOI:https://doi.org/10.1016/0360-3016(94)90228-3· OSTI ID:7060904

Ruifrok, A C.C.; Van Der Kogel, A J ^[1]; Stephens, L C ^[2]

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1. Univ. of Nijmegen (Netherlands)
2. Anderson Cancer Center, Houston, TX (United States)

Investigation of the age dependent single-dose radiation tolerance, latency to radiation myelopathy, and the histopathological changes after irradiation of the rat cervical spinal cord is presented. Rats were irradiated with graded single doses of 4 MV photons to the cervical spinal cord. When the rats showed definite signs of paresis of the forelegs, they were killed and processed for histological examination. The radiation dose resulting in paresis due to white matter damage in 50% of the animals (ED[sub 50]) after single dose irradiation was about 21.5 Gy at all ages [ge] 2 weeks. Only the Ed[sub 50] at 1 week was significantly lower. The latency to the development of paresis clearly changed with the age at irradiation, from about 2 weeks after irradiation at 1 week to 6-8 months after irradiation at age [ge] 8 weeks. The white matter damage was similar in all symptomatic animals studied. The most prominent were areas with diffuse demyelination and swollen axons, often with focal necrosis, accompanied by glial reaction. This was observed in all symptomatic animals, irrespective of the age at irradiation. Expression of vascular damage appeared to depend on the age at irradiation. Although the latency to myelopathy is clearly age dependent, single dose tolerance is not age dependent at age [ge] 2 weeks in the rat cervical spinal cord. The white matter damage is similar in all symptomatic animals studied, but the vasculopathies appear to be influenced by the age at irradiation. It is concluded that white matter damage and vascular damage are separate phenomena contributing to the development of radiation myelopathy, expression of which may depend on the radiation dose applied and the age at irradiation. 28 refs., 5 figs., 3 tabs.

• OSTI ID: 7060904
• Journal Information: International Journal of Radiation Oncology, Biology and Physics; (United States), Vol. 29:1; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
RATS
BIOLOGICAL RADIATION EFFECTS
SPINAL CORD
AGE DEPENDENCE
DOSE-RESPONSE RELATIONSHIPS
RADIOTHERAPY
SIDE EFFECTS
TIME DELAY
ANIMALS
BIOLOGICAL EFFECTS
CENTRAL NERVOUS SYSTEM
MAMMALS
MEDICINE
NERVOUS SYSTEM
NUCLEAR MEDICINE
RADIATION EFFECTS
RADIOLOGY
RODENTS
THERAPY
VERTEBRATES
560152* - Radiation Effects on Animals- Animals