Heat shock mRNA in mouse epidermis after UV irradiation

Total RNA from murine epidermis was extracted at different times after irradiation with erythemogenic doses of ultraviolet light (UVB or UVB/UVA) and hybridized to a DNA probe from the gene of a heat shock protein (hsp 70). An intense and transitory enrichment in RNA molecules hybridizing to the DNA probe was found between 15 and 120 min after irradiation, followed by a return to control levels over the next 70 h. Dose-response analysis indicates that 30 min after the irradiation, the relative amount of RNA hybridizing to the hsp 70 DNA probe increases with the dose (within the range explored: 0-180 mJ/cm2) up to values greater than 5 times the control.