Human Epidermal Cell Proliferation with Regard to Circadian Variation of Plasma Cortisol

Abstract

This study was performed in 6 healthy young men under analogous experimental conditions to investigate whether or not the epidermal proliferative activity is influenced by the physiological circadian rhythmicity of cortisol concentration in blood. Every 6 h of total duration of the experiments, blood samples were taken for radioimmunoassay of serum cortisol and skin punch biopsies (upper arm inside) were labelled in vitro by ³H-thymidine. In 4 out of 6 individuals, an inverse and time-shifted correlation between the combined serum cortisol levels and the epidermal ³H-LI could be found, i.e., a rise or decline of serum cortisol were followed by a lowered or elevated rate of epidermal LI 6 h later. In particular, a steep increase of serum cortisol from midnight to 6 a.m. correlated to a decrease of ³H-LI from 6 a.m. to noon. This indicates that in man the rate of the epidermal proliferative activity inversely depends, apart from other mechanisms of regulation, on the concentration and circadian periodicity of endogenous cortisol in blood. However, we failed to demonstrate a clear circadian rhythm of the epidermal proliferation, possibly due to the short duration of the experiments extended in each individual to 48 h only.

DNA flow cytometry on human epidermis. The effect of serial biopsy sampling at various times

“…Thus individually different reactions to external and internal stimuli connected with the period awake were suggested. The absence of evidence for diurnal rhythms in the S-fraction in normal human skin is in agreement with the reports of Pullmann et al (1974), Schell et al (1977) and Schell et al (1980), while Kahn, Weinstein & Frost (1968) and Thorud & Volden (1980) found minor suggestions of diurnal rhythms in ^HTdR-Iabelling indices or S-fractions in normal human skin.…”

“…In their classical animal studies on epidermal growth control, BuUough & Lawrence (i960) and Iversen, Bhangoo & Hansen (1974) experienced merely local effects of injury to epidermis. In human studies, however, it cannot be ruled out that consciousness of the procedures to be undertaken might interfere, as recently suggested by Schell et al (1980). The design of this study does not allow final statements on the existence of diurnal rhythms in the growth of human epidermis.…”

“…Frents, U.Meller and N.Keiding human studies. Both in man and in animals, cell kinetic variables are found to be rather unstable and sensitive to different stimuli with regard to both environmental conditions and local injury (Braun-Falco, Christophers & Kurban, 1967;Clausen & Lindmo, 1976;Wiley & Weinstein, 1979;Grove, 1980;Schell, Hornstein & Schwartz, 1980). Thus, in clinical trials demanding serial biopsies from one individual, the cell kinetic variables may be profoundly infiucnced by preceding biopsy trauma.…”

Sleep Deprivation Alters the Cell Population Kinetics In the Jejunum of the Male Syrian Hamster (Mesocricetus auratus)

“…1975;Akerstedt & Froberg, 1979). Schell, Hornstein & Schwarz (1980) and Schell et al (1981) reported an inverse relationship between cortisol levels and I , in human epidermis. The absence of a sleep deprivation effect on I , suggests that cortisol levels in sleep-deprived hamsters were not significantly different from those in sleeping hamsters.…”

Variations of cAMP in Epidermis and Plasma of Male Adult Subjects

“…Besides adrenaline-chalone com plexes [2-4] the diurnal variation of serum cortisol level influences the rate of epidermal DNA synthesis as recently demonstrated by Schell et al [12]. As another important regulatory component, the intracellular system of cyclic nucleotides (cAMP and cGMP) balances the kinetics of epidermal growth [16].…”