Proteome and Transcriptome in Irradiated Glands Figure 1. Effect of 15-Gy head and neck irradiation on saliva secretion. A. Saliva flow rate after irradiation: normalized, pilocarpine-induced saliva secretion from non-irradiated (control) and 4-, 8- and 12-week post-irradiation rats. The number of rats used in each experiment is indicated inside the bars. ***P,0.001 vs. control. B. H&E staining of rat submandibular gland tissue from control and irradiated rats. C. Representative 2-D electrophoretic analysis of pooled saliva before and after 15-Gy irradiation: saliva protein (45 mg) from non-treated animals, and animals 4 weeks, 8 weeks and 12 weeks post-irradiation were separated by 2-D electrophoresis. Proteins with reduced expression during the 12 weeks following IR are represented by red ellipses, those with higher expression by blue ellipses and those with erratic expression by black rectangles. D. Changes in normalized optical density ratios and MS identification of selected cluster spots after 15-Gy irradiation: identified spot proteins are shown in decreasing order of matched peptides. doi:10.1371/journal.pone.0040636.g001 PLoS ONE | www.plosone.org 3 July 2012 | Volume 7 | Issue 7 | e40636