Experimental animals and chemicals

Rats and their treatment were the same as in our earlier reports.41 Seventy-two 30-day-old male Wistar albino rats with an average weight of 58.0 ± 7.8 g were provided by the Experimental Animal Center of Shanxi Medical University of China. NaF was supplied by Sigma Company (USA). Goat anti-COL I polyclonal antibody was from Santa Cruz Biotechnology, Inc. Rabbit anti-DPP polyclonal antibody was purchased from Uscn Sciences Co. Ltd, Wuhan, China. Biotin-labeled anti-goat secondary antibody was supplied by Haoyang Biological Manufacture Co., Ltd, Tianjin, China. Biotin-labeled anti-rabbit secondary antibody was purchased from Uscn Sciences Co. Ltd, Wuhan, China. Trizol Reagent was purchased from Invitrogen (Carlsbad, CA, USA). The One-Step SYBR® RT-PCR kit and real time PCR primers were obtained from the Takara Biotechnology Company (Dalian, China). HE and Masson Trichrome kits were purchased from Baso Diagnostics, Inc., Zhuhai, China.