Decreased Saliva Secretion and Down-Regulation of AQP5 in Submandibular Gland in Irradiated Rats

Abstract Li, Z., Zhao, D., Gong, B., Xu, Y., Sun, H., Yang B. and Zhao, X. Decreased Saliva Secretion and Down-Regulation of AQP5 in Submandibular Gland in Irradiated Rats. Radiat. Res. 165, 678–687 (2006). The molecular mechanisms of radiation-induced xerostomia remain unclear. The purpose of this study was to investigate the alterations of aquaporins (AQPs) and Na+/K+-ATPase in irradiated rat submandibular glands and to test the hypothesis that down-regulation of AQP5 expression in irradiated salivary glands is one of the mechanisms of radiation-induced xerostomia. Saliva from control and irradiated rat submandibular glands was analyzed. The mRNA level of AQP5 in the submandibular glands was assessed by semi-quantitative RT-PCR and in situ hybridization. The protein expression of AQP5, AQP1 and Na+/K+-ATPase was determined by Western blotting and immunohistochemistry. The body weight, submandibular gland weight, and saliva secretion of irradiated rats significantly decreased by 12, 24 and 32% on day 3 a...