Effect of post-treatments with caffeine during G2 on the frequencies of chromosome-type aberrations produced by X-rays in human lymphocytes during G0 and G1.
Human lymphocytes were irradiated with X-rays in G0 and G1, grown in the presence of 5-bromodeoxyuridine, and harvested at different times from 48 to 80 h after stimulation. Some cultures were exposed to 2.5-5 mM caffeine during the last 3 h before harvesting. The frequencies of chromosome-type aberrations were scored in first division (M1) metaphases. The post-treatment with caffeine increased the frequencies of mitoses and chromosome-type aberrations in irradiated cultures. The results suggest that cells carrying chromosome-type aberrations are delayed in G2 and that caffeine increases the frequencies of aberrations in dividing cells by removing this G2-block.
Tanzarella
C
C
Centro Genetica Evoluzionistica, c/o Dipartimento Genetica Biologia Molecolare, Rome, Italy.
De Salvia
R
R
Degrassi
F
F
Palitti
F
F
Andersson
H C
HC
Hansson
K
K
Kihlman
B A
BA
D002110:Caffeine / Q000008:administration & dosage / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D002869:Chromosome Aberrations; D004260:DNA Repair / Q000187:drug effects; D004334:Drug Administration Schedule; D006801:Humans; D007399:Interphase; D008214:Lymphocytes / Q000166:cytology / Q000528:radiation effects*; D008938:Mitosis / Q000187:drug effects; D014965:X-Rays
D002110:Caffeine