Figure 5.

Effect of IPL irradiation on mRNA expression of type I and III procollagens of cultured skin fibroblasts. Cultured fibroblasts were treated with IPL irradiation (570–590 nm and 18 J/cm²) and the mRNA expression was measured after culturing irradiated fibroblasts for 1, 12, 24 and 48 h. Compared with sham irradiation, the mRNA expression levels of procollagen type I and III did not increase noticeably after cultured from 1 to 12 h. After the irradiated fibroblasts were cultured for 24 and 48 h, the expression levels of the procollagens were obviously increased (P<0.05) and the upregulatory effect of IPL was also time-dependent.