Abstract:
The histological and ultrastructural changes of skin of Wistar rats were compared with 10600nm CO2 dot laser
irradiation and external use of A acid preparation. The effects of dot matrix CO2 laser and Nd: YAG laser (quasi long pulse width 10600nm wavelength) on the expression of matrix metalloproteinase -1 (MMP-1) and matrix
metalloproteinase inhibitor -1 (TIMP-1) in skin of natural aging mice were investigated, and the skin tender mechanism was further explored. To explore the long-term efficacy and timeliness of 10600nm CO2 dot laser and A acid treatment, so as to provide reference for clinical practice. The skin of hair on the back of mice was irradiated with dot CO2 laser and Nd: YAG laser. They were taken at 2 weeks, 1 month and 3 months after irradiation respectively. The dynamic changes of skin HSP47, HSP70 and TGF - β 1 were detected by immunohistochemistry, and the difference of two laser irradiation effects was compared. 45 female Wistar rats were randomly divided into 9 groups. The back skin was used as the experimental observation area. After the depilation, the observation was divided into four parts by using the cross shaped marking line: the left side of the proximal end was the normal control group (A area). At the proximal end, the left side was the vitamin A acid group (B area). The right side of the tail was the combined treatment group (C area), and the right side of the proximal end was the dot laser group (D area). The C and D regions irradiated 10600 CO2 dot matrix laser 1 times at the beginning of the experiment. The parameters were: energy 15mJ, energy density 5%, frequency 300Hz. The fig. is square, 10mm * 10mm; after the laser irradiation, the B and C areas begin to wipe the 0.025% dimensional A cream every day for 3 weeks. The positive expression of MMP-1 and TIMP-1 in dot CO2 laser and Nd: YAG laser irradiation area was most obvious at 2 weeks. The MMP-1 gray value (115.14 + 5.23) and TIMP-1 gray value (104.01 + 3.15) of the dot matrix laser irradiated area were lower than the MMP-1 gray value (121.75 + 4.39) and TIMP-1 gray value (109.26 + 3.88) in the Nd: YAG laser irradiation area. That is, the positive expression of CO2 laser irradiation area was higher, and the difference was statistically significant (P < 0.05).
