The Effects of Parathyroid Hormone on the Alveolar Bone of Ovariectomized Rats
Abstract
Osteoporosis is a widespread metabolic disease of bone characterized by decreased bone mineral density and reduced quality of bone microarchitecture leading to increased fracture risk and fragility of the bones. Traditionally, the most common therapeutic approach for osteoporosis has been anti-resorptive medications. They promote mineralization by suppressing osteoclastogenesis and osteoclast function, culminating in suppression of bone turnover. However, it has been noted that anti-resorptives such as bisphosphonates cannot rebuild bone structure or bone mass as seen in post-menopausal women. Current treatment modalities also include osteoanabolics. In severe forms of osteoporosis, the use of osteoanabolics such as PTH helps to restore the bone mass through anabolic effects on osteoblasts. PTH has been known to enhance the bone microarchitectural properties by increasing the bone mineral density (BMD), by improving trabecular number and connectivity, and strengthening the resistance to mechanical fracture. Various mechanisms have been proposed to explain how the PTH can improve the quality of bone remodeling in patients with osteoporosis. Most of them are studied in the context of long bones. The molecular mechanism by which parathyroid hormone (PTH) acts in osteoporotic animal models, especially in the maxillary alveolar region have not been fully elucidated. It is important to understand the effects of osteoporosis on the alveolar bone morphology and homeostasis in the context of maxilla as we know it is more porous than mandible, and thus, prone to resorptive changes in osteoporosis. Moreover, understanding this process could also help us explore the role of PTH in other chronic diseases of the alveolar bone such as chronic periodontitis. Our hypothesis was to study the effects of ovariectomy/osteoporosis on the alveolar bone morphology and bone remodeling, and to elucidate the molecular mechanism of PTH treatment on the osteoporotic rats model. Herein, we used ovariectomized rat model and used the alveolar bone region of the maxillary first molar area as the region of interest.
This is one of the first study to highlight the morphologic, microarchitectural and molecular changes after osteoporosis in a rat maxillary alveolar region and to describe the role of PTH as a therapeutic effect to restore those osteoporotic changes.
Citation
Shrestha, Madhu (2022). The Effects of Parathyroid Hormone on the Alveolar Bone of Ovariectomized Rats. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /197429.