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Two Techniques to Create Hypoparathyroid Mice: Parathyroidectomy Using GFP Glands and Diphtheria-Toxin-Mediated Parathyroid Ablation
Published on: March 14, 2017
Influence of parathyroid hormone on bone cell ultrastructure
Clinical Orthopaedics and Related Research
|May 1, 1981
Summary
Parathyroid hormone (PTH) causes bone cell changes during rising calcium levels in rats. These morphologic alterations in osteocytes and osteoblasts indicate their role in calcium regulation.
Area of Science:
- Bone biology
- Cellular morphology
- Calcium homeostasis
Background:
- Parathyroid hormone (PTH) is a key regulator of calcium levels.
- Osteocytes and osteoblasts are bone cells involved in bone remodeling.
- Understanding the cellular mechanisms of PTH action is crucial for calcium metabolism research.
Purpose of the Study:
- To investigate the morphologic changes in bone cells (osteocytes and osteoblasts) induced by parathyroid hormone (PTH).
- To determine if these cellular changes correlate with plasma calcium level fluctuations.
- To explore the role of bone cells in maintaining calcium homeostasis.
Main Methods:
- Rats were subjected to thyroparathyroidectomy and injected with PTH, or fasted.
- Tibias were analyzed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM).
- Extracellular tracer (lanthanum) was used to assess cell permeability and intercellular spaces.
Main Results:
- PTH injection and fasting induced significant morphologic changes in osteocytes and osteoblasts, including altered cell shape, surface microvilli, blebs, and rough endoplasmic reticulum cisternae.
- These changes occurred when plasma calcium levels were rising due to PTH stimulation.
- SEM and TEM revealed increased cellular activity and potential for enhanced pinocytosis following PTH stimulation.
Conclusions:
- Bone cells, including osteocytes and lining cells, exhibit distinct morphologic changes in response to PTH.
- These cellular alterations are associated with periods of changing plasma calcium concentrations.
- The study supports the hypothesis that bone cells actively participate in the maintenance of plasma calcium levels.
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