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On circadian rhythms in human epidermal cell proliferation.
G Frentz1, U Møller, P Hölmich
1Department of Dermatology, Finsen Institute, Rigshospitalet, Copenhagen, Denmark.
Acta Dermato-Venereologica
|January 1, 1991
Summary
Human skin cell growth shows a daily rhythm, with cell division (G2-M phase) peaking at certain times. This circadian rhythm in epidermal cell proliferation may impact skin disease treatments.
Area of Science:
- Dermatology
- Chronobiology
- Cell Biology
Background:
- Diurnal variations in human epidermal cell proliferation are significant for understanding skin diseases.
- Previous research suggests potential daily rhythms in skin cell growth.
Purpose of the Study:
- To evaluate diurnal rhythms in human epidermal cell proliferation.
- To assess the consistency of these rhythms over a 48-hour period.
Main Methods:
- Skin biopsies were collected every 4 hours for 48 hours from two individuals under synchronized conditions.
- Epidermal cell proliferation was measured by DNA content analysis, assessing the fraction of cells in S and G2-M phases.
- Cortisol excretion in urine was monitored to verify diurnal body function consistency.
Main Results:
- Circadian rhythmicity was observed in the fraction of cells in the G2-M phase for the initial 32 hours.
- No consistent time-of-day variation was found in the fraction of cells in the S-phase.
Conclusions:
- Human epidermal cell proliferation exhibits a circadian rhythm, particularly in the G2-M phase.
- The findings suggest that the timing of cell division in the epidermis follows a daily pattern, which could be relevant for dermatological treatments.