Effect of mechanical pressure on c-fos and on the mitotic activity of epidermal cells.
A dosed mechanical pressure of 12.5 kg/cm2 applied for 1 min on depilated mouse skin did not cause cellular death or visible alterations of the cellular ultrastructures. However, it had a strong effect on the mitotic cycle of the epidermal cells-stimulating the cells to enter the mitotic cycle and temporarily blocking the G1-->S transition. This effect was strictly limited to the pressed area of the skin. The proto-oncogene c-fos was induced within the first 2 min following application of the pressure. The level of c-fos mRNA showed two peaks during the next 24 h. The first slight peak was preceded by a rapid increase in the cAMP level in the pressed skin, the second-by a fall in the cAMP concentration. A model is suggested to explain the observed effects by reversible functional damage of the cellular membrane affecting the enzymes maintaining the steady state level of cAMP.
Tsanev
R
R
Institute of Molecular Biology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
Yaneva
J
J
Vaptzarova
K
K
Markov
D
D
D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism / Q000648:ultrastructure; D005786:Gene Expression Regulation; D016762:Genes, fos; D008297:Male; D051379:Mice; D008854:Microscopy, Electron; D008938:Mitosis; D011312:Pressure; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
D012333:RNA, Messenger; D000242:Cyclic AMP