Assessment of the effect of laser irradiation at different wavelengths on autophagy in a rat model of mucositis

It is known that high dose radiation has an effect on tissue healing, but tissue healing does not occur when low dose radiation is applied. To clarify this issue, we compare the treatment success rate of low dose radiation with programmed cell death mechanisms on wounded tissue. We used 35 adult Wistar-Albino rats in present study. All animals were injected with 100 mg/kg of 5-fluorouracil(5-FU) on the first day and 65mg/kg of 5-FU on the third day. The tips of 18-gauge needles were used to develop a superficial scratching on the left cheek pouch mucosa by dragging in a linear movement on third and fifth days. After mucositis formation was clinically detected, animals were divided into five groups. Different wavelenghts of laser irridations were performed on four groups once daily for four days. Laser irridation was not applied on the control group. Oval excisional biopsy was performed to get the tissue from the left cheek. Molecular analysis assessments were performed. The results were evaluated by normalization and statistics analysis. We found Ulk1, Beclin1, and Atg5 expression levels were increased in Nd:YAG group. This increase showed 1,064 nm laser is to activate the autophagic mechanism. However, in the diode applications, we found Beclin1, Atg10, Atg5, and Atg7 expressions numerically decreased. The reduction of expression of these genes leads us to think that it might be due to the effect of drug (5-FU) used to form model. Expressions of therapeutic genes increase to ensure haemostasis, but in our study, expressions were found to decrease. More detailed studies are needed.