Enhancement of the efficacy of x-irradiation by pentobarbital in a rodent brain-tumor model

Journal Article · Tue May 01 04:00:00 EDT 1990 · Journal of Neurosurgery; (USA)

DOI:https://doi.org/10.3171/jns.1990.72.5.0745· OSTI ID:6833302

Olson, J J; Friedman, R; Orr, K; Delaney, T; Oldfield, E H ^[1]

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1. National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD (USA)

Radiation therapy is an important component of brain tumor treatment, but its efficacy is limited by its toxicity to the surrounding normal tissue. Pentobarbital acts as a cerebral radioprotectant, but the selectivity of its protection for the central nervous system has not been demonstrated. To determine if pentobarbital also protects tumor against ionizing radiation, five groups of Fischer 344 rats were observed after exposure to varying combinations of the presence or absence of implanted tumor, pentobarbital, and radiation treatment. The first three groups underwent cerebral implantations of a suspension of 9L gliosarcoma cells. Group 1 was left untreated and served as tumor-bearing controls. Group 2 received 30 Gy of whole-brain x-irradiation without anesthesia 8 days after tumor implantation. Group 3 received the same radiation treatment 15 minutes after pretreatment with 60 mg/kg of pentobarbital intraperitoneally. Groups 4 and 5 served as radiation controls, receiving 30 Gy of x-irradiation while awake and 30 Gy of x-irradiation after pentobarbital administration, respectively. Survival was calculated from the death of the last tumor-bearing rat. The mean survival time in tumor-bearing control rats was 20.8 +/- 2.6 days (+/- standard deviation). X-irradiation alone significantly enhanced the period of survival in rats implanted with the 9L tumor (29.7 +/- 5.6 days, p less than 0.03). Further significant prolongation of survival was seen with the addition of pentobarbital to the treatment regimen (39.9 +/- 13.5 days, p less than 0.01). Nontumor-bearing rats irradiated while awake (Group 4) survived 30.9 +/- 2.3 days. All of their pentobarbital-anesthetized counterparts in Group 5 survived. If pentobarbital had offered radioprotection to the tumor, then Group 3 would have had a shorter survival period than Group 2.

• OSTI ID: 6833302
• Journal Information: Journal of Neurosurgery; (USA), Journal Name: Journal of Neurosurgery; (USA) Vol. 72:5; ISSN 0022-3085; ISSN JONSA
• Country of Publication: United States
• Language: English

Related Subjects

560152* -- Radiation Effects on Animals-- Animals
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANESTHETICS
ANIMALS
AZINES
BARBITURATES
BIOLOGICAL MODELS
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM DEPRESSANTS
DISEASES
DOSES
DRUGS
ELECTROMAGNETIC RADIATION
GLIOMAS
HETEROCYCLIC COMPOUNDS
HYPNOTICS AND SEDATIVES
IONIZING RADIATIONS
MAMMALS
NEOPLASMS
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
PYRIMIDINES
RADIATION DOSES
RADIATION PROTECTION
RADIATIONS
RADIOSENSITIVITY EFFECTS
RATS
RODENTS
SURVIVAL CURVES
VERTEBRATES
X RADIATION