EXPRESSION OF AQUAPORINS 1 AND 5 IN PAROTID GLANDS OF RATS AFTER VOLUMETRIC MODULATED ARC THERAPY AND LASER THERAPY

Abstract

Objective: The experimental study investigated the expression of type-1 and type-5 aquaporins (AQPs) in samples from parotid glands of rats irradiated by volumetric modulated arc therapy (VMAT) and subjected to low-level laser therapy (LLLT) at different times. Study design: Thirty Wistar rats distributed in control groups without intervention (CG), only LLLT (LG) and only radiotherapy (RG), and the use of immediate LLLT 24 hours (IEG) and late 120 hours (LEG) after radiotherapy. VMAT was single dose (12 Gy), and LLLT with laser AsGaAl (660 nm, 100 mW), spot 0.0028 cm2, at 3 points in the right parotid gland region (60 seconds and 70 J/cm2/d), for 10 consecutive days until euthanasia. The parotid glands were dissected and prepared, and the gene expression of the AQPs evaluated by quantitative polymerase chain reaction (qPCR) using specific probes TaqMan and HPRT gene as constitutive controls. Results: All groups presented AQP expression without significant difference in comparison to CG; however, mean expression of AQPs 1 and 5 was higher in groups that used LLLT, even at later times. Conclusion: VMAT does not cause destruction of AQPs, and the use of late LLLT can provide maintenance and increase of these proteins that participate in the process of salivary secretion. Financial support: CAPES Objective: The experimental study investigated the expression of type-1 and type-5 aquaporins (AQPs) in samples from parotid glands of rats irradiated by volumetric modulated arc therapy (VMAT) and subjected to low-level laser therapy (LLLT) at different times. Study design: Thirty Wistar rats distributed in control groups without intervention (CG), only LLLT (LG) and only radiotherapy (RG), and the use of immediate LLLT 24 hours (IEG) and late 120 hours (LEG) after radiotherapy. VMAT was single dose (12 Gy), and LLLT with laser AsGaAl (660 nm, 100 mW), spot 0.0028 cm2, at 3 points in the right parotid gland region (60 seconds and 70 J/cm2/d), for 10 consecutive days until euthanasia. The parotid glands were dissected and prepared, and the gene expression of the AQPs evaluated by quantitative polymerase chain reaction (qPCR) using specific probes TaqMan and HPRT gene as constitutive controls. Results: All groups presented AQP expression without significant difference in comparison to CG; however, mean expression of AQPs 1 and 5 was higher in groups that used LLLT, even at later times. Conclusion: VMAT does not cause destruction of AQPs, and the use of late LLLT can provide maintenance and increase of these proteins that participate in the process of salivary secretion. Financial support: CAPES