Tanzarella C, De Salvia R, Degrassi F, Palitti F, Andersson H C, Hansson K, Kihlman B A
Centro Genetica Evoluzionistica, c/o Dipartimento Genetica Biologia Molecolare, Rome, Italy.
Mutagenesis. 1986 Jan;1(1):41-4. doi: 10.1093/mutage/1.1.41.
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.
