Since sister chromatid exchange (SCE) relates directly to DNA synthesis which is circadian periodic, this study examines whether a circadian rhythm also characterizes SCEs. In 4-hourly blood samples collected for 48 hours on three diurnally active, nocturnally resting subjects with no family history of chromosome aberrations or instability, a circadian rhythm is demonstrable with an acrophase occuring around 14:45. The circadian amplitude is only of the older of 10% of the MESOR in untreated cultures or in cultures exposed to cefodizime. It remains more or less unchanged in cultures exposed to mitomycin-C, while the MESOR increases by about a factor of 2. In studies of human chromosome aberrations, the circadian rhythmicity of SCE should be taken into consideration.
|Original language||English (US)|
|Number of pages||3|
|State||Published - 1995|
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- Circadian rhythm
- Human chromosomes
- Sister chromatic exchanges