The requirement of parathyroid tissue for bone mineral loss during lactation was investigated. Lactating rats parathyroidectomized (PTX) at day 2 of lactation and consuming a 2% calcium diet are hypercalcemic and hypophosphatemic at day 13 of lactation. The high-calcium diet supports normal growth of pups nursing PTX mothers. PTX lactating rats mobilize bone mineral to the same extent as euparathyroid lactating rats consuming the same diet. Non-lactating PTX rats lose no bone mineral over a similar time period, indicating lactation-specific bone mineral mobilization in the absence of parathyroid tissue. PTX rats were verified to have physiologically insignificant amounts of parathyroid tissue, as evidenced by severe hypocalcemia and/or death in each rat after a shift from a 2% calcium to a 0.02% calcium diet. These results conclusively demonstrate that lactation-associated bone mineral mobilization does not require parathyroid hormone or parathyroid tissue.
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http://dx.doi.org/10.1152/ajpendo.1992.262.2.E230 | DOI Listing |
Gac Med Mex
January 2025
Centre for Metabolic Bone Diseases, University of Sheffield, Sheffield, United Kingdom.
FRAX, a risk calculator that provides individualized 10-year probabilities of hip and major osteoporotic fracture, has been widely used for fracture risk assessment since its launch in 2008. It is now incorporated into very many guidelines worldwide to inform osteoporosis management. In this review, we explore the development of FRAX and how it enhances fracture risk prediction as compared to use of bone mineral density alone, as well as approaches to utilizing FRAX in determining intervention and assessment thresholds.
View Article and Find Full Text PDFBiogerontology
January 2025
Department of Physiology, School of Medicine, University of Louisville, Louisville, KY, 40202, USA.
Alzheimer's disease (AD) and osteoporosis (OP) pose distinct but interconnected health challenges, both significantly impacting the aging population. AD, a neurodegenerative disorder characterized by memory impairment and cognitive decline, is primarily associated with the accumulation of abnormally folded amyloid beta (Aβ) peptides and neurofibrillary tangles in the brain. OP, a skeletal disorder marked by low bone mineral density, involves dysregulation of bone remodeling and is associated with an increased risk of fractures.
View Article and Find Full Text PDFBiometals
January 2025
School of Environment and Climate, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China.
Bone mineral density (BMD) measured by T-score is strongly associated with bone health, but research on its association with metals in humans body remains limited. To investigate the relationship between metal exposure and BMD, numbers of 159 participants in eastern China were studied. Urine and blood samples were collected and levels of 20 metals in the samples were measured using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS).
View Article and Find Full Text PDFACS Biomater Sci Eng
January 2025
Engineering Research Center of Chinese Ministry of Education for Biological Diagnosis, Treatment and Protection Technology and Equipment, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an 710072, China.
Fracture healing is a complex process during which the bone restores its structural and mechanical integrity. Collagen networks and minerals are the fundamental components to rebuild the bone matrix in callus. It has been recognized that bone quality could be impaired during aging.
View Article and Find Full Text PDFClin Cosmet Investig Dent
January 2025
Department of Conservative Dentistry and Endodontics, Manipal College of Dental Sciences, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India.
Purpose: Thyroid hormones have a catabolic effect on bone mineral homeostasis. Hypothyroid patients have shown changes in bone mineral density with increased risk for osteoporosis and bone fractures. Radiomorphometric parameters on panoramic images are good indicators of bone mineral density.
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