Modelled microgravity does not modify the yield of chromosome aberrations induced by high-energy protons in human lymphocytes.
The aim was to evaluate the effect of modelled microgravity on radiation-induced chromosome aberrations (CAs). G0 peripheral blood lymphocytes were exposed to 60 MeV protons or 250 kVp X-rays in the dose range 0-6 Gy, and allowed to repair DNA damage for 24 h under either normal gravity or microgravity modelled by the NASA-designed rotating-wall bioreactor. Cells were then stimulated to proliferate by phytohaemagglutinin (PHA) under normal gravity conditions and prematurely condensed chromosomes were harvested after 48 h. CAs were scored in chromosomes 1 and 2 by fluorescence in-situ hybridization. Proliferation gravisensitivity was examined by cell growth curves and by morphological evaluation of mitogen-induced activation. Cell replication rounds were monitored by bromodeoxyuridine labelling. Modelled microgravity markedly reduced PHA-mediated lymphocyte blastogenesis and cell growth. However, no significant differences between normal gravity and modelled microgravity were found in the dose-response curves for the induction of aberrant cells or total interchromosomal exchange frequency. Rotating-wall bioreactor-based microgravity reproduced space-related alterations of mitogen stimulation in human lymphocytes but did not affect the yield of CAs induced by low-linear energy transfer radiation.
Manti
L
L
Department of Physical Sciences, University of Naples Federico II, and National Institute for Nuclear Physics (INFN), Section of Naples, Italy. manti@na.infn.it
Durante
M
M
Cirrone
G A P
GA
Grossi
G
G
Lattuada
M
M
Pugliese
M
M
Sabini
M G
MG
Scampoli
P
P
Valastro
L
L
Gialanella
G
G
D049109:Cell Proliferation / Q000528:radiation effects; D048429:Cell Size / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D002869:Chromosome Aberrations / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects*; D011522:Protons; D018474:Weightlessness Simulation / Q000379:methods*
D011522:Protons