The purpose of the present study was to determine the effects of supraphysiologic doses of triiodothyronine (T(3)) on skeletal metabolism, calcium balance, and the calciotropic hormones. Seven healthy, lean men were studied in an inpatient metabolic unit over a 63-day period. All volunteers received oral T(3) at doses of 50-75 microg/d. There was a prompt and sustained increase in calciuria and an overall net negative calcium balance. The pattern of changes in serum osteocalcin, urinary deoxypyridinoline (DPD)/creatinine ratio, and serum bone-specific alkaline phosphatase indicated an early increase in bone resorption followed by a late, incomplete compensatory increase in bone formation. Cumulative net calcium loss was 18.5 +/- 5.4 g over the 63-day treatment period, averaging 218.5 +/- 41.4 mg/d. This represents 0.22% +/- 0.075% of the total skeletal calcium content. The cumulative net calcium loss over the 63-day treatment period was highly correlated with the change in DPD (r = -0.95, p = 0.001). Prompt increases in corrected serum calcium values resulted in serum intact parathyroid hormone (iPTH) levels decreasing by 30.4% (p = 0.08). Bone mineral density showed no change. We conclude that T(3) accelerates bone turnover and that bone formation does not increase acutely to prevent bone loss.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1089/105072503321669848 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Metabolically stable apelin analogs: development and functional role in water balance and cardiovascular function.
Clin Sci (Lond)
January 2025
Center for Interdisciplinary Research in Biology, College de France, Institut National de la Santé et de la Recherche Médicale, Paris, France.
Apelin, a (neuro) vasoactive peptide, plays a prominent role in controlling water balance and cardiovascular functions. Apelin and its receptor co-localize with vasopressin in magnocellular vasopressinergic neurons. Apelin receptors (Apelin-Rs) are also expressed in the collecting ducts of the kidney, where vasopressin type 2 receptors are also present.
View Article and Find Full Text PDFCellulose nanofiber reinforced curcumin-infused calcium phosphate silicate cement for various bone-tissue engineering application.
Front Oncol
January 2025
Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China.
Introduction: This study utilized a injectable curcumin (Cur)-infused calcium phosphate silicate cement (CPSC) for addressing defects caused by bone cancer, and evaluated its promoting bone regeneration and exerting cytotoxic effects on osteosarcoma cells.
Methods: The material's physicochemical properties, biocompatibility with osteoblasts, and cytotoxicity toward osteosarcoma cells were rigorously analyzed.
Results: The findings demonstrate that CPSC-Cur signicantly prolongs the setting time, which can be optimized by adding silanized cellulose nanober (CNF-SH) to achieve a balance between workability and mechanical strength.
The E3-ligase Siah2 activates mitochondrial quality control in neurons to maintain energy metabolism during ischemic brain tolerance.
Cell Death Dis
January 2025
Division of Pharmacology, Department of Neuroscience, School of Medicine, University of Naples "Federico II", Naples, Italy.
Mitochondrial quality control is crucial for the homeostasis of the mitochondrial network. The balance between mitophagy and biogenesis is needed to reduce cerebral ischemia-induced cell death. Ischemic preconditioning (IPC) represents an adaptation mechanism of CNS that increases tolerance to lethal cerebral ischemia.
View Article and Find Full Text PDFCaML: Chemistry-informed machine learning explains mutual changes between protein conformations and calcium ions in calcium-binding proteins using structural and topological features.
Protein Sci
February 2025
Department of Physics, University of Washington, Seattle, Washington, USA.
Proteins' flexibility is a feature in communicating changes in cell signaling instigated by binding with secondary messengers, such as calcium ions, associated with the coordination of muscle contraction, neurotransmitter release, and gene expression. When binding with the disordered parts of a protein, calcium ions must balance their charge states with the shape of calcium-binding proteins and their versatile pool of partners depending on the circumstances they transmit. Accurately determining the ionic charges of those ions is essential for understanding their role in such processes.
View Article and Find Full Text PDFFunctional properties of aged hypothalamic cells.
Vitam Horm
January 2025
Department Normal Physiology, Yaroslavl State Medical University, Yaroslavl, Russia. Electronic address:
The hypothalamus, in addition to controlling the main body's vital functions, is also involved in aging regulation. The aging process in the hypothalamus is accompanied by disturbed intracellular pathways, including Ca signaling and neuronal excitability in the brain. Intrinsic electrophysiological properties of individual neurons and synaptic transmission between cells is disrupted in the central nervous system of old animals.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!