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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
Parathyroid hormone gene expression in hypophosphatemic rats
R Kilav1, J Silver, T Naveh-Many
1Minerva Center for Calcium and Bone Metabolism, Hadassah University Hospital, Jerusalem, Israel.
The Journal of Clinical Investigation
|July 1, 1995
Summary
Dietary phosphate intake influences parathyroid hormone (PTH) regulation. Low phosphate diets decrease PTH mRNA and levels, while high phosphate diets increase PTH mRNA, indicating phosphate
Area of Science:
- Endocrinology
- Bone Metabolism
- Mineral Homeostasis
Background:
- Phosphate is a critical regulator of bone metabolism.
- Parathyroid hormone (PTH) plays a key role in calcium and phosphate homeostasis.
- The regulation of PTH by dietary phosphate is not fully understood.
Purpose of the Study:
- To investigate the in vivo regulation of parathyroid hormone (PTH) by dietary phosphate.
- To elucidate the effects of varying dietary phosphate levels on PTH mRNA and serum PTH concentrations.
- To determine the mechanism by which phosphate influences PTH expression.
Main Methods:
- Weanling rats were fed diets with controlled low, normal, and high phosphate content for 3 weeks.
- Serum calcium, phosphate, 1,25(OH)2D3, and immunoreactive PTH levels were measured.
- PTH mRNA levels were assessed using in situ hybridization and nuclear transcript run-ons.
Main Results:
- Low phosphate diet induced hypophosphatemia, hypercalcemia, increased 1,25(OH)2D3, and significantly decreased PTH mRNA and serum PTH.
- High phosphate diet led to increased PTH mRNA levels.
- Hypophosphatemia decreased PTH mRNA in all parathyroid cells, an effect that was posttranscriptional and independent of calcium and vitamin D levels.
Conclusions:
- Dietary phosphate is a significant regulator of parathyroid hormone (PTH) synthesis and secretion.
- Low phosphate levels suppress PTH mRNA expression via a posttranscriptional mechanism.
- Phosphate, alongside calcium and vitamin D, plays a crucial role in regulating parathyroid function.
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