Fig. 7.

Matrix contents in gingival explants are increased by nifedipine and phenytoin ex vivo. a. Fibronectin contents in gingival tissues treated with nifedipine or phenytoin or without drug ex vivo. Human gingival connective tissues cultured with nifedipine (100 ng/ml), phenytoin (30 μg/ml), or without the drug for 2 weeks were stained for fibronectin. Fluorescent immunoreactivity for fibronectin was detected with Cy5-conjugated secondary antibody (red). Nuclei are stained with Hoechst 3342 dye (blue). Arrows indicate fibroblasts-positive for fibronectin. Yellow dotted line outlines the border between the oral epithelium and the connective tissue. b. Collagen contents in human gingival connective tissues cultured with nifedipine (100 ng/ml), phenytoin (30 μg/ml), or without the drug for 2 weeks had higher collagen contents indicated by Masson’s trichrome, Van Gieson’s, and Picrosirius red staining. Polarized light microscope was used to image the sections stained with picrosirius red. Scale bar, 50 μm. c. Hydroxyproline contents normalized to weights of gingival tissue explants cultured with nifedipine (100 ng/ml), phenytoin (30 μg/ml), or without the drug for 2 weeks. Data represents mean fold hydroxyproline levels ± STD relative to control (no drug) condition of three independent experiments in triplicates. Data was analyzed using one-way ANOVA with Bonferroni’s multiple comparisons test (*p < 0.05)