PTH is a major regulator of renal proximal tubule 1,25(OH)2D3 biosynthesis. However, the intracellular pathways involved in PTH activation of the mitochondrial 25-hydroxyvitamin D3-1 alpha-hydroxylase (1-OHase) remain unknown. PTH can activate both the adenylate cyclase/protein kinase A (PKA) and the plasma membrane phospholipase C/protein kinase C (PKC) pathways. The present study was undertak...

Elevation of serum parathyroid hormone (PTH) in patients with medullary thyroid cancer (MTC) is usually found in multiple endocrine neoplasia type 2A (MEN2A). However, ectopic production of PTH is rare and its molecular etiology remains largely uninvestigated. We report a case of ectopic production of PTH by a sporadic MTC. The etiology of ectopic PTH gene expression was examined, focusing on G...

Secondary hyperparathyroidism is one of the most common and serious abnormalities in patients with chronic kidney disease. Despite recent progress in the treatment of hyperparathyroidism, advanced uraemic nodular hyperplasia, or rarely, sporadic primary adenoma accompanied by chronic renal failure is usually resistant to medical treatment and requires parathyroidectomy [1,2]. Spontaneous remiss...

Objective This study was performed to investigate the effect of parathyroid hormone (PTH) on healing in osteoporotic fractures via a phospholipase C (PLC)-independent pathway and explore the mechanism of PTH-mediated bone formation. Methods Ninety-six 12-week-old C57BL/6J female mice underwent bilateral ovariectomy. One month later, the lower third of the femur was fractured and the mice were t...

Intermittent administration of parathyroid hormone (PTH) dramatically increases bone mass and currently is one of the most effective treatments for osteoporosis. However, the detailed mechanisms are still largely unknown. Here we demonstrate that conditioned media from PTH-treated osteoblastic and osteocytic cells contain soluble chemotactic factors for bone marrow mesenchymal progenitors, whic...

The Cbfa1/Runx2 (referred to herein as Cbfa1) transcription factor has been shown to be essential for osteoblast differentiation and bone formation during embryogenesis. PTH given intermittently is a proven bone anabolic agent. Here, we investigated whether PTH regulates the expression and/or activity of Cbfa1 in osteoblastic cells and in a rat metatarsal organ culture assay. PTH was found to r...

We studied the effects of PTH on the expression of tumor necrosis factor-related activation-induced cytokine (TRANCE), osteoprotegerin (OPG), and receptor activator of NF kappaB (RANK) messenger RNA (mRNA) in cultured murine bone marrow, calvaria, and osteoblasts. TRANCE, OPG, and RANK are recently identified regulators of osteoclast formation. Bone marrow cells were cultured with or without PT...

UNLABELLED PTH stimulates bone formation in Fgfr3 knockout mice through promotion of proliferation and differentiation in osteoblasts. INTRODUCTION Previous studies showed that endogenous fibroblast growth factor 2 (FGF-2) is required for parathyroid hormone (PTH)-stimulated bone anabolic effects, however, the exact mechanisms by which PTH stimulate bone formation and the function of FGF rece...

Inorganic phosphate (Pi) is absorbed by proximal tubules through a cellular pathway that is inhibited by parathyroid hormone (PTH). The calcium-sensing receptor (CaSR) is expressed on apical membranes of proximal tubules. In the present studies, we determined the effect of luminal and/or basolateral PTH on phosphate absorption and tested the hypothesis that CaSR activation blocks PTH-inhibitabl...

Objective To assess posttonsillectomy hemorrhage (PTH), associated nonoperative readmissions/revisits, and reoperations in children. Data Sources MEDLINE, EMBASE, and the Cochrane Library. Review Methods Two investigators independently screened studies against predetermined criteria and extracted key data. Investigators independently assessed study risk of bias and the strength of the evidence ...