Reverse transcriptase–polymerase chain reaction (RT-PCR) and Western blot analyses of submandibular gland (SMG) RNAs and proteins to verify the expression of Toll-like receptor-4 (TLR-4). Total RNA or homogenate proteins were subjected to RT-PCR and Western blot analyses. Other experimental conditions are described in the text. (a) RT-PCR; (b) Western blotting. Sizes of DNA markers in (a) are 1500, 1200, 1000, 900, 800, 700, 600, 500, 400, 300, 200 and 100 bp. T, TLR-4 mRNA amplification; A, β-actin amplification; N, no added RNA; M, DNA markers; Ab, anti-TLR-4 polyclonal antibody; p-Ab, peptide-preabsorbed anti-TLR-4 polyclonal antibody.