Structural Adaptations in the Rat Tibia Bone Induced by Pregnancy and Lactation Confer Protective Effects Against Future Estrogen Deficiency
| Autor: | Chantal M.J. de Bakker, X. Sherry Liu, Ling Qin, Wei Tong, Tiao Lin, Laurel Leavitt, Yihan Li, Hongbo Zhao, Wei Ju Tseng |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty medicine.drug_class Endocrinology Diabetes and Metabolism Osteoporosis Population 030209 endocrinology & metabolism 03 medical and health sciences 0302 clinical medicine In vivo Internal medicine Lactation medicine Orthopedics and Sports Medicine education Bone mineral Pregnancy education.field_of_study business.industry medicine.disease 030104 developmental biology Endocrinology medicine.anatomical_structure Estrogen Cortical bone business |
| Zdroj: | Journal of Bone and Mineral Research. 33:2165-2176 |
| ISSN: | 0884-0431 |
| DOI: | 10.1002/jbmr.3559 |
| Popis: | The female skeleton undergoes substantial structural changes during the course of reproduction. Although bone mineral density recovers postweaning, reproduction may induce permanent alterations in maternal bone microarchitecture. However, epidemiological studies suggest that a history of pregnancy and/or lactation does not increase the risk of postmenopausal osteoporosis or fracture and may even have a protective effect. Our study aimed to explain this paradox by using a rat model, combined with in vivo micro-computed tomography (μCT) imaging and bone histomorphometry, to track the changes in bone structure and cellular activities in response to estrogen deficiency following ovariectomy (OVX) in rats with and without a reproductive history. Our results demonstrated that a history of reproduction results in an altered skeletal response to estrogen-deficiency-induced bone loss later in life. Prior to OVX, rats with a reproductive history had lower trabecular bone mass, altered trabecular microarchitecture, and more robust cortical structure at the proximal tibia when compared to virgins. After OVX, these rats underwent a lower rate of trabecular bone loss than virgins, with minimal structural deterioration. As a result, by 12 weeks post-OVX, rats with a reproductive history had similar trabecular bone mass, elevated trabecular thickness, and increased robustness of cortical bone when compared to virgins, resulting in greater bone stiffness. Further evaluation suggested that reproductive-history-induced differences in post-OVX trabecular bone loss were likely due to differences in baseline trabecular microarchitecture, particularly trabecular thickness. Rats with a reproductive history had a larger population of thick trabeculae, which may be protective against post-OVX trabecular connectivity deterioration and bone loss. Taken together, these findings indicate that reproduction-associated changes in bone microarchitecture appear to reduce the rate of bone loss induced by estrogen deficiency later in life, and thereby exert a long-term protective effect on bone strength. © 2018 American Society for Bone and Mineral Research. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text