Parathyroid hormone enhances osteogenesis in a rat model for extraosseous bone formation

1984 ◽  
Vol 104 (4_Supplb) ◽  
pp. S14 ◽  
Author(s):  
J. M. GOTTSWINTER ◽  
H. FLECHTNER ◽  
R. LÖWENSTEIN ◽  
R. ZIEGLER ◽  
G. DELLING
Keyword(s):  
Parathyroid Hormone ◽  
Bone Formation ◽  
Rat Model

Effects of Parathyroid Hormone on Bone Formation in a Rat Model for Chronic Alcohol Abuse

2001 ◽  
Vol 25 (5) ◽  
pp. 667-671 ◽  
Author(s):  
Russell T. Turner ◽  
Glenda L. Evans ◽  
Minzhi Zhang ◽  
Jean D. Sibonga
Keyword(s):  
Parathyroid Hormone ◽  
Alcohol Abuse ◽  
Bone Formation ◽  
Rat Model ◽  
Chronic Alcohol ◽  
Chronic Alcohol Abuse

scholarly journals The Effects of Parathyroid Hormone Applied at Different Regimes on the Trochanteric Region of the Femur in Ovariectomized Rat Model of Osteoporosis

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
M. Tezval ◽  
A. Banhardt ◽  
S. Sehmisch ◽  
L. Kolios ◽  
U. Schmelz ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Formation ◽  
Cross Sections ◽  
Rat Model ◽  
Sham Group ◽  
Formation Rate ◽  
Sprague Dawley ◽  
Bone Formation Rate ◽  
Sprague Dawley Rats ◽  
Trochanteric Region

This study aims to investigate the effects of two application frequencies of parathyroid hormone on the trochanteric region of rat femur. Forty-three-month-old female Sprague-Dawley rats were divided into 4 groups (n=10/group). Three groups were ovariectomized, and 8 weeks later they were administered the following treatments (5 weeks): soy-free diet (OVX), subcutaneously injected PTH (0.040 mg/kg) 5 days a week (PTH 5x/w), subcutaneously injected PTH (0.040 mg/kg) every 2 days (PTH e2d), and a sham group. The values of the biomechanical and histomorphometric parameters showed higher results in 5x/w animals in comparison to the OVX and PTH 2ed groups. The ratio between bone diameter/marrow diameter (B.Dm/Ma.Dm) in subtrochanteric cross sections did not show any significant differences between PTH 5x/w and PTH e2d. The increased bone formation rate was observed under PTH treatment in both groups mainly at the endosteal side. The endosteum seems here to be one of the targets of PTH with an accelerate bone formation and a pronounced filling-in of intracortical cavities with higher intensity for the PTH 5x/w in comparison to PTH e2d rats.

P1237TISSUE-NONSPECIFIC ALKALINE PHOSPHATASE, A CULPRIT DURING ARTERIAL MEDIA CALCIFICATION BUT INDISPENSABLE DURING PHYSIOLOGICAL BONE FORMATION/-MINERALIZATION IN RATS

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Britt Opdebeeck ◽  
José Millan Luis ◽  
Anthony Pinkerton ◽  
Anja Verhulst ◽  
Patrick D'Haese ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Bone Formation ◽  
Vascular Calcification ◽  
Rat Model ◽  
Bone Mineralization ◽  
Calcium Content ◽  
Marker Genes ◽  
Peripheral Arteries ◽  
Calcium Phosphorus ◽  
Chondrogenic Marker

Abstract Background and Aims Vascular media calcification is frequently seen in elderly and patients with chronic kidney disease (CKD), diabetes and osteoporosis. Pyrophosphate is a well-known calcification inhibitor that binds to nascent hydroxyapatite crystals and prevents further incorporation of inorganic phosphate into these crystals. However, the enzyme tissue-nonspecific alkaline phosphatase (TNAP), which is highly expressed in calcified arteries, degrades extracellular pyrophosphate into phosphate ions, by which pyrophosphate loses its ability to block vascular calcification. Here, we aimed to evaluate whether a TNAP inhibitor is able to prevent the development of arterial calcification in a rat model of warfarin-induced vascular calcification. Method To induce vascular calcification, rats received a diet containing 0.30% warfarin and 0.15% vitamin K1 throughout the entire study and were subjected to the following daily treatments: (i) vehicle (n=10) or (ii) 10 mg/kg/day TNAP-inhibitor (n=10) administered via an intraperitoneal catheter from start of the study until sacrifice at week 7. Calcium, phosphorus and parathyroid hormone (PTH) levels were determined in serum samples as these are important determinants of vascular calcification. As TNAP is also expressed in the liver, serum alanine aminotransferase (ALT) and aspartate (AST) levels were analyzed. At sacrifice, vascular calcification was evaluated by measurement of the total calcium content in the arteries and quantification of the area % calcification on Von Kossa stained sections of the aorta. The mRNA expression of osteo/chondrogenic marker genes (runx2, TNAP, SOX9, collagen 1 and collagen 2) was analyzed in the aorta by qPCR to verify whether vascular smooth muscle cells underwent reprogramming towards bone-like cells. Bone histomorphometry was performed on the left tibia to measure static and dynamic bone parameters as TNAP also regulates physiological bone mineralization. Results No differences in serum calcium, phosphorus and PTH levels was observed between both study groups. Warfarin exposure resulted in distinct calcification in the aorta and peripheral arteries. Daily dosing with the TNAP inhibitor (10 mg/kg/day) for 7 weeks significantly reduced vascular calcification as indicated by a significant decrease in calcium content in the aorta (vehicle 3.84±0.64 mg calcium/g wet tissue vs TNAP inhibitor 0.70±0.23 mg calcium/g wet tissue) and peripheral arteries and a distinct reduction in area % calcification on Von Kossa stained aortic sections as compared to vehicle condition. The inhibitory effects of SBI-425 on vascular calcification were without altering serum liver markers ALT and AST levels. Furthermore, TNAP-inhibitor SBI-425 did not modulate the mRNA expression of osteo/chondrogenic marker genes runx2, TNAP, SOX9, collagen 1 and 2. Dosing with SBI-425 resulted in decreased bone formation rate and mineral apposition rate, and increased osteoid maturation time and this without significant changes in osteoclast- and eroded perimeter. Conclusion Dosing with TNAP inhibitor SBI-425 significantly reduced the calcification in the aorta and peripheral arteries of a rat model of warfarin-induced vascular calcification and this without affecting liver function. However, suppression of TNAP activity should be limited in order to maintain adequate physiological bone mineralization.

scholarly journals Sclerostin Antibody Treatment Increases Bone Formation, Bone Mass, and Bone Strength in a Rat Model of Postmenopausal Osteoporosis*

2009 ◽  
Vol 24 (4) ◽  
pp. 578-588 ◽  
Author(s):  
Xiaodong Li ◽  
Michael S Ominsky ◽  
Kelly S Warmington ◽  
Sean Morony ◽  
Jianhua Gong ◽  
...  
Keyword(s):  
Bone Formation ◽  
Bone Mass ◽  
Postmenopausal Osteoporosis ◽  
Bone Strength ◽  
Rat Model ◽  
Antibody Treatment ◽  
Sclerostin Antibody

scholarly journals SLPI is a critical mediator that controls PTH-induced bone formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Akito Morimoto ◽  
Junichi Kikuta ◽  
Keizo Nishikawa ◽  
Takao Sudo ◽  
Maki Uenaka ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Bone Formation ◽  
Protease Inhibitor ◽  
Bone Metabolism ◽  
Serine Protease ◽  
Serine Protease Inhibitor ◽  
Secretory Leukocyte Protease Inhibitor ◽  
Bone Imaging ◽  
Genetic Ablation

AbstractOsteoclastic bone resorption and osteoblastic bone formation/replenishment are closely coupled in bone metabolism. Anabolic parathyroid hormone (PTH), which is commonly used for treating osteoporosis, shifts the balance from osteoclastic to osteoblastic, although it is unclear how these cells are coordinately regulated by PTH. Here, we identify a serine protease inhibitor, secretory leukocyte protease inhibitor (SLPI), as a critical mediator that is involved in the PTH-mediated shift to the osteoblastic phase. Slpi is highly upregulated in osteoblasts by PTH, while genetic ablation of Slpi severely impairs PTH-induced bone formation. Slpi induction in osteoblasts enhances its differentiation, and increases osteoblast–osteoclast contact, thereby suppressing osteoclastic function. Intravital bone imaging reveals that the PTH-mediated association between osteoblasts and osteoclasts is disrupted in the absence of SLPI. Collectively, these results demonstrate that SLPI regulates the communication between osteoblasts and osteoclasts to promote PTH-induced bone anabolism.

scholarly journals Parathyroid hormone induces bone formation in phosphorylation-deficient PTHR1 knockin mice

2012 ◽  
Vol 302 (10) ◽  
pp. E1183-E1188 ◽  
Author(s):  
Nabanita S. Datta ◽  
Tareq A. Samra ◽  
Abdul B. Abou-Samra
Keyword(s):  
Parathyroid Hormone ◽  
Bone Formation ◽  
Physiological Role ◽  
Receptor Internalization ◽  
Mineral Density ◽  
Trabecular Thickness ◽  
Receptor Complexes ◽  
Diaphyseal Bone ◽  
Anabolic Action

Activation of G protein-coupled receptors by agonists leads to receptor phosphorylation, internalization of ligand receptor complexes, and desensitization of hormonal response. The role of parathyroid hormone (PTH) receptor 1, PTHR1, is well characterized and known to regulate cellular responsiveness in vitro. However, the role of PTHR1 phosphorylation in bone formation is yet to be investigated. We have previously demonstrated that impaired internalization and sustained cAMP stimulation of phosphorylation-deficient (PD) PTHR1 leads to exaggerated cAMP response to subcutaneous PTH infusion in a PD knockin mouse model. To understand the physiological role of receptor internalization on PTH bone anabolic action, we examined bone parameters of wild-type (WT) and PD knockin female and male mice following PTH treatment. We found a decrease in total and diaphyseal bone mineral density in female but not in male PD mice compared with WT controls at 3–6 mo of age. This effect was attenuated at older age groups. PTH administration displayed increased bone volume and trabecular thickness in the vertebrae and distal femora of both WT and PD animals. These results suggest that PTHR1 phosphorylation does not play a major role in the anabolic action of PTH.

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