Abstract Menopause induces oral bone loss, leading to various oral diseases. Mastication importantly affects bone metabolism in the jawbone. Objective: To analyze the effect of enhanced masticatory force on osteoprotegerin (OPG), receptor activator of nuclear factor kappa B ligand (RANKL), and mechano–growth factor (MGF) in alveolar bone of ovariectomized rats and to study the mechanics mechanism of the alveolar bone of ovariectomized rats response to enhanced masticatory force. Methodology: Thirty Sprague Dawley rats were randomly divided into three groups: sham–operation group (fat around the removed ovary + normal hard diet), model group (ovariectomy + normal hard diet), and experimental group (ovariectomy + high hard diet). It was a 2–month experiment. Enzyme–linked immunosorbent assay (ELISA) detected serum estradiol (E2), osteocalcin (BGP) and alkaline phosphatase (ALP) in rats. Bone histomorphometric indices in the third molar region of maxilla were detected by micro-CT; protein expressions of OPG, RANKL, and MGF in the third molar region of maxilla was detected by Western blot; and gene expression of OPG, RANKL, and MGF in the third molar region of maxilla was detected by Quantitative Real–Time PCR. Results: Comparing with model group, serum E2 in experimental group increased but not significantly, serum BGP and serum ALP in experimental group decreased but not significantly, OPG in experimental group in alveolar bone increased significantly, RANKL in experimental group in alveolar bone decreased significantly, RANKL/OPG ratio in experimental group decreased significantly, MGF in experimental group in alveolar bone increased significantly, bone volume to total volume fraction increased significantly in experimental group, trabecular thickness increased significantly in experimental group, and trabecular separation decreased significantly in experimental group. Conclusion: Enhanced masticatory force affected the expression of OPG, RANKL, and MGF in alveolar bone of ovariectomized rats, improved the quality of jaw bone of ovariectomized rats, and delayed oral bone loss by ovariectomy.

Abstract Purpose: To evaluate the effects of single intravenous administration of Dexmedetomidine (DEX) on hemodynamics in rabbits. Methods: A total of 32 New Zealand white rabbits were randomly divided into the control group (Group C), Group D1 (2.75 μg/kg), Group D2 (5.5 μg/kg), and Group D3 (8.25 μg/kg) to compare systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), central venous pressure (CVP), left ventricular systolic pressure (LVSP), left ventricular end-stage diastolic pressure (LVEDP), left ventricular developmental pressure (LVDP), +dp/dtmax, -dp/dtmax, and t-dp/dtmax at different time points. Results: The levels of SBP, DBP, HR, LVSP, and LVEDP in Group D1, D2, and D3 were lower than that of Group C from T1 to T5 (P<0.05), but there was no significant difference at T6 and T7 (P>0.05). Compared with T0, the levels of SBP, DBP, HR, LVSP, LVEDP, and left arterial pressure (LAP) from T1 to T7 were decreased (P<0.05), but there was no significant difference in the other indexes (P>0.05). Conclusion: Dexmedetomidine can decrease blood pressure and heart rate in rabbits in a dose-dependent manner, but there is no effect on the myocardial systolic and diastolic function.