Research Paper Volume 14, Issue 15 pp 6028—6046

Figure 2. Ascorbic acid upregulates muscarinic and adrenergic receptors in aging SAMP1/kl -/- mice. (A–D) Age-related muscarinic (M1/M3AchR) and adrenergic receptor (ADRβ1/β2) alterations in the salivary gland. Total mRNA was isolated from salivary gland tissues of SAMP1/kl+/+ and SAMP1/kl-/- mice. Quantification of endogenous mRNA expression was performed by quantitative reverse transcription-polymerase chain reaction (qRT–PCR). *p < 0.05. (E–H) Effects of ascorbic acid treatment in the salivary glands of SAMP1/kl -/- mice. SAMP1/kl -/- mice were fed 100 mg/kg ascorbic acid orally daily. Muscarinic and adrenergic receptor expression in the salivary glands of SAMP1/kl-/- mice treated with ascorbic acid was analyzed by quantitative RT–PCR or Western blotting. *p < 0.05. (I, J) Immunohistochemistry staining of M1 and M3AchR in tissue sections of salivary glands from ascorbic acid-treated SAMP1/kl -/- mice. Data are presented as the mean ± standard deviation (SD). Each group was compared with the mean of the control.