The effects of estrogen deficiency on cortical bone microporosity and mineralization
| Autor: | Timothy G. Bromage, Susannah P. Fritton, Stephen B. Doty, Adriana I. Larriera, Paolo E. Palacio-Mancheno, Divya Sharma, Luis Cardoso, J. Christopher Fritton, Vittorio Gatti |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Vascular porosity medicine.medical_specialty Histology Physiology medicine.drug_class Ovariectomy Endocrinology Diabetes and Metabolism Osteoporosis 030209 endocrinology & metabolism Bone mechanotransduction Bone tissue Mechanotransduction Cellular Osteocytes Article Bone and Bones Rats Sprague-Dawley 03 medical and health sciences Imaging Three-Dimensional 0302 clinical medicine Bone Density Internal medicine Osteocyte lacunar porosity medicine Animals Mechanotransduction Tibia Chemistry Estrogens X-Ray Microtomography medicine.disease Rats Disease Models Animal 030104 developmental biology medicine.anatomical_structure Endocrinology Estrogen Osteocyte Cortical porosity Ovariectomized rat Female Cortical bone Porosity Cancellous bone Algorithms |
| Zdroj: | Bone. 110:1-10 |
| ISSN: | 8756-3282 |
| DOI: | 10.1016/j.bone.2018.01.019 |
| Popis: | Recent studies have demonstrated matrix-mineral alterations in bone tissue surrounding osteocytes in estrogen-deficient animals.While cortical bone porosity has been shown to be a contributor to the mechanical properties of bone tissue, little analysis has been done to investigate the effects of estrogen deficiency on bone's microporosities, including the vascular and osteocyte lacunar porosities. In this study we examined alterations in cortical bone microporosity, mineralization, and cancellous bone architecture due to estrogen deficiency in the ovariectomized rat model of postmenopausal osteoporosis. Twenty-week-old female Sprague���Dawley rats were subjected to either ovariectomy or sham surgery. Six weeks post-surgery tibiae were analyzed using high-resolution micro-CT, backscattered electron imaging, nanoindentation, and dynamic histomorphometry. Estrogen deficiency caused an increase in cortical bone vascular porosity, with enlarged vascular pores and little change in tissue mineral density in the proximal tibial metaphysis. Measurements of cancellous architecture corresponded to previous studies reporting a decrease in bone volume fraction, an increase in trabecular separation, and a decrease in trabecular number in the proximal tibia due to estrogen deficiency. Nanoindentation results showed no differences in matrix stiffness in osteocyte-rich areas of the proximal tibia of estrogen-deficient rats, and bone labeling and backscattered electron imaging showed no significant changes in mineralization around the vascular pores. The findings demonstrate local surface alterations of vascular pores due to estrogen deficiency. An increase in cortical vascular porosity may diminish bone strength as well as alter bone mechanotransduction via interstitial fluid flow, both of which could contribute to bone fragility during postmenopausal osteoporosis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect