title: Molecular mechanism of damage and repair of mouse thymus lymphocytes induced by radiation.
abstract: OBJECTIVE
  To investigate the role of apoptosis in radiation-induced mouse thymus lymphocyte damage and repair and provide the basis for understanding the molecular mechanism of radiation-induced lymphocyte damage and repair as well as the prevention and treatment of acute radiation sickness.
  
  
  METHODS
  We studied the dynamic changes of apoptosis of mouse thymus lymphocytes and the expression of bax and bcl-2 gene products after 2, 4, 6 and 8 Gy of whole body gamma-irradiation using in situ terminal labeling, DNA electrophoresis and immunohistochemical techniques.
  
  
  RESULTS
  At the early stage after irradiation, the percentage of apoptotic lymphocytes increased rapidly in accordance with the increasing of radiation doses, while the counts of the thymus and peripheral lymphocytes decreased sharply, showing an opposite change to lymphocyte apoptosis. After 6 Gy gamma-irradiation, typical morphological characteristics of thymus apoptotic lymphocytes in early, middle and late stages were found by transmission electron microscopy. The thymus lymphocytes displayed characteristic DNA ladders 4 hr and 8 hr after 2-6 Gy gamma-irradiation,using DNA gel electrophoresis techniques. Abnormal expression of bcl-2 and bax gene products were shown in irradiated lymphocytes.
  
  
  CONCLUSIONS
  Apoptosis plays an important role in the process of radiation-induced mouse thymus lymphocyte damage and repair. Bcl-2 and Bax proteins may regulate the process of lymphocyte apoptosis.
authors.affiliation: Department of Experimental Pathology, Institute of Radiation Medicine, Beijing 100850, China. gaoyb@nic.bmi.ac.cn
authors.forename: Yufang
authors.initials: Y
authors.lastname: Cui
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.forename: Shuxia
authors.initials: S
authors.lastname: Wu
authors.forename: Linlu
authors.initials: L
authors.lastname: Gao
authors.forename: Yabing
authors.initials: Y
authors.lastname: Gao
authors.forename: Ruiyun
authors.initials: R
authors.lastname: Peng
authors.forename: Xuemei
authors.initials: X
authors.lastname: Cui
authors.forename: Chengqi
authors.initials: C
authors.lastname: Xiong
authors.forename: Wenhua
authors.initials: W
authors.lastname: Hu
authors.forename: Dewen
authors.initials: D
authors.lastname: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D008214:Lymphocytes / Q000502:physiology / Q000528:radiation effects*; D008297:Male; D051379:Mice; D011518:Proto-Oncogene Proteins / Q000032:analysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D013950:Thymus Gland / Q000473:pathology / Q000528:radiation effects; D013997:Time Factors; D051028:bcl-2-Associated X Protein
chemical_list: C494827:Bax protein, mouse; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein