An animal model of prophylactic cranial irradiation: Histologic effects at acute, early and delayed stages

• Published in: International journal of radiation oncology, biology, physics Vol. 18; no. 5; pp. 1051 - 1060
• Main Authors: Mildenberger, Marianne, Beach, Thomas G., McGeer, Edith G., Ludgate, Charles M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.1990
• Subjects: Acetylcholinesterase - metabolism; ANIMALS; BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BIOLOGICAL EFFECTS; BIOLOGICAL MODELS; BIOLOGICAL RADIATION EFFECTS; BODY; BRAIN; Brain - enzymology; Brain - metabolism; Brain - pathology; Brain - radiation effects; Brain Neoplasms - prevention & control; Brain Neoplasms - secondary; CARBON-CARBON LYASES; CARBOXY-LYASES; CARBOXYLESTERASES; CENTRAL NERVOUS SYSTEM; CHOLINESTERASE; COBALT 60; COBALT ISOTOPES; DECARBOXYLASES; ENZYMES; ESTERASES; FRACTIONATED IRRADIATION; Glial Fibrillary Acidic Protein - metabolism; Glutamate Decarboxylase - metabolism; HYDROLASES; HYDROXYLASES; Immunohistochemistry; INTERMEDIATE MASS NUCLEI; INTERNAL CONVERSION RADIOISOTOPES; IRRADIATION; ISOMERIC TRANSITION ISOTOPES; ISOTOPES; Lung cancer; LYASES; Male; MAMMALS; Microglia; MINUTES LIVING RADIOISOTOPES; NERVOUS SYSTEM; NUCLEI; ODD-ODD NUCLEI; ORGANS; OXIDOREDUCTASES; Prophylactic brain irradiation; RADIATION EFFECTS; RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; RADIOISOTOPES; RATS; Rats, Inbred Strains; RODENTS; VERTEBRATES; YEARS LIVING RADIOISOT 560151 > Radiation Effects on Animals > Man; Immunohistochemistry; Prophylactic brain irradiation; Radiation effects; Lung cancer; Microglia
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/0360-3016(90)90440-U

Wistar rats (body wt. 200 g) were subjected to a fractionated course of radiation similar to that used in prophylactic brain irradiation for small cell carcinoma of the lung (2000 cGy in 5 fractions over 5 days with 60Co). Effects of this regimen were assessed by histologic examination of brain sections at 1 week, 1 month and 6 months post-irradiation. With conventional stains there were no apparent differences between control and irradiated brains at any of the post-irradiation intervals. Immunohistochemistry for neurotransmitter synthetic enzymes tyrosine hydroxylase and glutamate decarboxylase, as well as histochemistry for acetylcholinesterase, failed to uncover any changes in the irradiated animals. Immunohistochemistry for glial fibrillary acidic protein, an astrocyte marker, also showed no differences in the irradiated groups. However, an antibody against a major histocompatibility complex, class II antigen (OX-6) revealed a microglial response in grey and white matter beginning at 1 month and increasing up to the 6 month post-irradiation interval. The neuroanatomical basis for this microglial response was suggested by the results of silver stains for nerve axons, which revealed axonal loss in striatal white matter bundles in a pattern implicating vascular insufficiency.