Ovarian hormone depletion affects cortical bone quality differently on different skeletal envelopes.
The physical properties of bone tissue are determined by the organic and mineral matrix, and are one aspect of bone quality. As such, the properties of mineral and matrix are a major contributor to bone strength, independent of bone mass. Cortical bone quality may differ regionally on the three skeletal envelopes that compose it. Each of these envelopes may be affected differently by ovarian hormone depletion. Identifying how these regions vary in their tissue adaptive response to ovarian hormones can inform our understanding of how tissue quality contributes to overall bone strength in postmenopausal women. We analyzed humeri from monkeys that were either SHAM-operated or ovariectomized. Raman microspectroscopic analysis was performed as a function of tissue age based on the presence of multiple fluorescent double labels, to determine whether bone compositional properties (mineral/matrix ratio, tissue water, glycosaminoglycan, lipid, and pyridinoline contents, and mineral maturity/crystallinity) are similar between periosteal, osteonal, and endosteal surfaces, as well as to determine the effects of ovarian hormone depletion on them. The results indicate that mineral and organic matrix characteristics, and kinetics of mineral and organic matrix modifications as a function of tissue age are different at periosteal vs. osteonal and endosteal surfaces. Ovarian hormone depletion affects the three cortical surfaces (periosteal, osteonal, endosteal) differently. While ovarian hormone depletion does not significantly affect the quality of either the osteoid or the most recently mineralized tissue, it significantly affects the rate of subsequent mineral accumulation, as well as the kinetics of organic matrix modifications, culminating in significant differences within interstitial bone. These results highlight the complexity of the cortical bone compartments, add to existing knowledge on the effects of ovarian hormone depletion on local cortical bone properties, and may contribute to a better understanding of the location specific action of drugs used in the management of postmenopausal osteoporosis.
Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Heinrich Collin Str. 30, A-1140 Vienna, Austria. Electronic address: lpaschalis@gmx.net.
E P
EP
Paschalis
Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Heinrich Collin Str. 30, A-1140 Vienna, Austria.
S
S
Gamsjaeger
Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Heinrich Collin Str. 30, A-1140 Vienna, Austria.
N
N
Hassler
Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Heinrich Collin Str. 30, A-1140 Vienna, Austria.
K
K
Klaushofer
Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Biomedical Engineering, Indiana University-Purdue University, Indianapolis (IUPUI), Indianapolis, IN 46202, USA.
D
D
Burr
D000818:Animals; D015519:Bone Density / Q000187:drug effects; D001857:Bone Matrix / Q000187:drug effects / Q000378:metabolism; D000071538:Cortical Bone / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006025:Glycosaminoglycans / Q000378:metabolism; D006253:Haversian System / Q000187:drug effects / Q000502:physiology; D006728:Hormones / Q000494:pharmacology*; D006811:Humerus / Q000187:drug effects / Q000502:physiology; D007700:Kinetics; D008252:Macaca fascicularis; D010053:Ovary / Q000378:metabolism*
D006025:Glycosaminoglycans; D006728:Hormones
Bone quality; Cortical bone; Humerus; Osteoporosis; Ovariectomy; Raman spectroscopy