A comparison of the mutagenic and apoptotic effects of tritiated water and acute or chronic caesium-137 gamma exposure on spleen T lymphocytes on normal and p53-deficient mice

Int J Radiat Biol. 2009 Dec;85(12):1082-8. doi: 10.3109/09553000903242131.

Abstract

Purpose: This study was carried out to compare the mutagenic effects on spleen T lymphocytes of mice exposed to tritiated water (HTO) and chronic or acute (137)Cs gamma irradiation.

Materials and methods: p53 wild type (p53(+/+)) and p53 null type (p53(-/-)) mice were exposed to a total dose of 3 Gy of HTO, chronic (137)Cs and acute (137)Cs.

Results: In spontaneous T-cell receptor (TCR) variant fractions and fractions following exposure to HTO, chronic (137)Cs and acute (137)Cs, TCR variant fractions in p53(+/+) mice were 5.9 x 10(-4), 9.8 x 10(-4), 6.4 x 10(-4) and 20.1 x 10(-4), respectively. In contrast, those fractions were increased in p53(-/-) mice to 11.2 x 10(-4), 18.8 x 10(-4), 15.7 x 10(-4) and 31.3 x 10(-4), respectively. The frequency of apoptotic cells of the spleen 12 h after HTO injection increased to 5.0% in p53(+/+) mice, but did not increase at all in p53(-/-) mice.

Conclusions: When compared on the basis of induced TCR variant fractions in p53(-/-) mice, HTO (7.6 x 10(-4)) was 1.7 times more mutagenic than chronic (137)Cs (4.5 x 10(-4)), but 2.6 times less mutagenic than acute (137)Cs gamma irradiation (20.1 x 10(-4)).

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Animals
  • Apoptosis / physiology
  • Apoptosis / radiation effects*
  • Cesium Radioisotopes / adverse effects*
  • Chronic Disease
  • Dose-Response Relationship, Radiation
  • Gamma Rays / adverse effects*
  • Mice
  • Mice, Inbred C57BL
  • Mutagens / adverse effects
  • Radiation Injuries, Experimental
  • Receptors, Antigen, T-Cell / metabolism
  • Spleen / immunology*
  • Spleen / pathology
  • Spleen / radiation effects
  • T-Lymphocytes / immunology
  • T-Lymphocytes / pathology
  • T-Lymphocytes / radiation effects*
  • Tritium / adverse effects*
  • Tumor Suppressor Protein p53 / deficiency*
  • Tumor Suppressor Protein p53 / genetics

Substances

  • Cesium Radioisotopes
  • Mutagens
  • Receptors, Antigen, T-Cell
  • Tumor Suppressor Protein p53
  • Tritium