Regenerative Proliferation of Mouse Epidermal Cells Following Adhesive Tape Stripping

Abstract

The proliferating cells of mouse epidermis (basal cells) can be separated from the non‐proliferating cells (differentiating cells) (Laerum, 1969) and brought into a mono‐disperse suspension. This makes it possible to determine the cell cycle distributions (e.g. the relative number of cells in the G^ S and (G2+ M) phases of the cell cycle) of the basal cell population by means of micro‐flow fluorometry. To study the regenerative cell proliferation in epidermis in more detail, changes in cell cycle distributions were observed by means of micro‐flow fluorometry during the first 48 hr following adhesive tape stripping. 3H‐TdR uptake (LI and grain count distribution) and mitotic rate (colcemid method) were also observed. An initial accumulation of G2 cells was observed 2 hr after stripping, followed by a subsequent decrease to less than half the control level. This was followed by an increase of cells entering mitosis from an initial depression to a first peak between 5 and 9 hr which could be satisfactorily explained by the changes in the G2 pool. After an initial depression of the S phase parameters, three peaks with intervals of about 12 hr followed. The cells in these peaks could be followed as cohorts through the G2 phase and mitosis, indicating a partial synchrony of cell cycle passage, with a shortening of the mean generation time of basal cells from 83‐3 hr to about 12 hr. The oscillations of the proportion of cells in G2 phase indicated a rapid passage through this cell cycle phase. The S phase duration was within the normal range but showed a moderate decrease and the Gj phase duration was decreased to a minimum. In rapidly proliferating epidermis there was a good correlation between change in the number of labelled cells and cells with S phase DNA content. This shows that micro‐flow fluorometry is a rapid method for the study of cell kinetics in a perturbed cell system in vivo.

1,25‐dihydroxyvitamin D3 and the vitamin D analogue KH1060 induce hyperproliferation in normal mouse epidermis

“…6B). The tnechanism of these early accutnulations of Gn cells is unknown, but is probably non-specific since it is also obsetved after treatment with other hyperplasiogens (15,16,(22)(23)(24)(25).…”

Growth and cell kinetics of human hair papilla cells in vitro. An autoradiographic and flow cytometric study

“…D. Bassukas et al in the dermal papilla of vellus follicles of bald stumptailed macaques treated topically with minoxidil (Uno 1989). Additionally the isolation and cultivation of HPC (Jahoda & Oliver 1981, Messenger 1984, Katsuoka et al 1986) clearly underline the proliferation capacity of these cells.…”

“…The hair papilla represents a fundamental anatomical and functional component of the proliferating part of the hair follicle bulb (Oliver 1967, Jahoda, Horne & Oliver 1984. The 'characteristic' cells of the hair papilla, the hair papilla cells (HPC), which are most probably a distinct fibroblast species , Katsuoka et al 1986, Messenger 1989, show a synthetic and excretory activity synchronous to the hair cycle (Montagna et al 1952, Couchman, King & McCarthy 1990). This synchrony, along with the well-known correlation of the papilla size and hair diameter (Van Scott & Eke1 1958), implies that HPC substantially influence hair growth.…”

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

“…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.…”