J Korean Med Sci.  2002 Apr;17(2):242-248. 10.3346/jkms.2002.17.2.242.

Expression of TNF-alpha and TGF-beta1 in the Rat Brain After a Single High-Dose Irradiation

• Kim SH
• Lim DJ
• Chung YG
• Cho TH
• Lim SJ
• Kim WJ
• Suh JK

• KMID: 648684
• DOI: http://doi.org/10.3346/jkms.2002.17.2.242

Abstract

Cytokines and growth factors are important regulatory proteins controlling the growth and differentiation of normal and malignant glial cells. In this study, we investigated the expression and origin of tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta 1 (TGF-beta 1) in the subacute brain injury after a single high-dose irradiation using 60 Sprague-Dawley rats. The right cerebral hemispheres of rats were exposed to a single 10 Gy dose of gamma rays using Ir-192. The radiation effect was assessed at 1 week, 2 weeks, 4 weeks, 6 weeks, and 8 weeks after irradiation, and the results were compared with those in sham operation group. Histological changes characteristic of radiation injury were correlated with the duration after the single dose irradiation. The loss of cortical thickness also increased with the lapse of time after irradiation. The TNF-alpha expression in the irradiated cerebral hemispheres was significantly increased compared with that in the sham operation group. TGF-beta 1 expression was also increased in the irradiated hemispheres. Immunohistochemical study revealed that TGF-beta 1 was expressed predominantly by infiltrating macrophages and astrocytes around the necrotic areas. These findings indicate that TNF-alpha and TGF-beta 1 may play prominent roles in the radiation injuries after a single high-dose irradiation.

Keyword

Cranial Irradiation; Radiation Injuries; Cytokines; Tumor Necrosis Factor-alpha; Transforming Growth Factor- beta1

MeSH Terms

Animals
Brain/immunology/pathology/*radiation effects
Dose-Response Relationship, Radiation
Immunohistochemistry/methods
Rats
Rats, Sprague-Dawley
Time Factors
Transforming Growth Factor beta/*biosynthesis
Transforming Growth Factor beta1
Tumor Necrosis Factor-alpha/*biosynthesis