scholarly journals Direct extraction and assay of bone tissue collagenase and its relation to parathyroid-hormone-induced bone resorption

1986 ◽  
Vol 239 (3) ◽  
pp. 793-796 ◽  
Author(s):  
Y Eeckhout ◽  
J M Delaissé ◽  
G Vaes
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Bone Tissue ◽  
Direct Extraction ◽  
Latent Form ◽  
Fetal Mouse ◽  
Quantitative Extraction

A method has been developed for the quantitative extraction of collagenase from as little as one 19-day-fetal-mouse calvarium. About 20-40 munits of collagenase are extracted per mg of tissue, all in a latent form that, after proper activation, shows the typical properties of mammalian collagenase. Culturing the calvaria for 2 days with parathyroid hormone (PTH) increases their procollagenase content up to 3-fold and induces bone resorption. Both PTH effects are prevented by cycloheximide, but not by indomethacin. Calcitonin inhibits resorption without affecting the PTH-induced procollagenase synthesis. The role of this synthesis is discussed in relation to the mechanisms of bone resorption.

A HORMONAL ASSESSMENT OF BOVINE PARTURIENT PARESIS: EVIDENCE FOR A ROLE OF OESTROGEN

1981 ◽  
Vol 88 (2) ◽  
pp. 161-171 ◽  
Author(s):  
B. W. HOLLIS ◽  
H. H. DRAPER ◽  
J. H. BURTON ◽  
R. J. ETCHES
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Plasma Levels ◽  
Post Partum ◽  
Comparative Assessment ◽  
Hormonal Control ◽  
Elevated Plasma ◽  
Calcium Phosphorus ◽  
Parturient Paresis

A comparative assessment was made of the hormonal control of calcium homeostasis in eight dairy cows which developed parturient paresis and in seven normal animals from the same herd. Plasma levels of calcium, phosphorus, magnesium, free hydroxyproline, 25-hydroxycholecalciferol (25-OHD), 1,25-dihydroxycholecalciferol (1,25-(OH)2D), parathyroid hormone, calcitonin, prolactin and oestrogen were monitored from 30 days prepartum to 15 days post partum. Prepartum levels of plasma calcium, hydroxyproline and calcitonin were depressed in the paretic animals, and plasma levels of phosphorus and oestrogen were elevated. Plasma levels of 25-OHD remained stable in both groups, whereas levels of 1,25-(OH)2D, parathyroid hormone and prolactin rose sharply at parturition. Plasma hydroxyproline, an index of bone resorption, began to rise 2 days prepartum in the control cows but not until 2 days post partum in the paretic cows. The data indicate that bone resorption was inhibited in the paretic group at the onset of lactation, and that a decreased capacity for bone resorption is a major factor in the susceptibility of some cows to this disease. The failure of the paretic animals to resorb bone was not associated with an inability to synthesize the calcium-mobilizing hormones parathyroid hormone or 1,25-(OH)2D, or to regulate the production of calcitonin. However, hypocalcaemia in the affected animals was associated with a significantly higher plasma level of oestrogen (a known inhibitor of bone resorption) in the immediate prepartum period. Following parturition, plasma levels of oestrogen fell rapidly and active bone resorption ensued in the paretic animals.

Role of parathyroid hormone in regulation of main calcium fluxes in rats.

1977 ◽  
Vol 232 (6) ◽  
pp. E535
Author(s):  
B Haldimann ◽  
J P Bonjour ◽  
H Fleisch
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Bone Formation ◽  
Bone Turnover ◽  
Linear Correlation ◽  
Constant Amount ◽  
Calcium Fluxes ◽  
Growing Rats

The effect of calcium deprivation on the various calcium fluxes was studied in growing rats either sham-operated (SHAM), thyroparathyroidectomized (TPTX), or thyroparathyroidectomized and supplemented with parathyroid hormone (PTH) (TPTX + PTH). In SHAM rats a decrease in the net absorption of calcium (Vna) has no influence on calcemia or on bone formation (Vo+), but leads to an increase in bone resorption (Vo-). In TPTX rats a decrease in Vna induces a decrease in calcemia and in Vo+ but still causes an increase in Vo-. The same is true in TPTX + PTH rats although all the variables measured are increased. In TPTX rats, both without and with PTH, a linear correlation exists between calcemia and Vo+ suggesting that calcemia influences bone formation. Furthermore, it appears that PTH is important in regulating bone turnover, but that the adaptation of Vo- to a change in Vna can occur in the absence or in the presence of a constant amount of this hormone. The mechanism of regulating this adaptation of bone resorption is still unknown.

Role of parathyroid hormone in mediating age-related changes in bone resorption in men

2003 ◽  
Vol 14 (8) ◽  
pp. 631-636 ◽  
Author(s):  
Kurt A. Kennel ◽  
B. Lawrence Riggs ◽  
Sara J. Achenbach ◽  
Ann L. Oberg ◽  
Sundeep Khosla
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Age Related ◽  
Age Related Changes

scholarly journals The Role of Parathyroid Hormone in Alveolar Bone Resorption on Postmenopausal Women

2020 ◽  
Vol 14 (1) ◽  
pp. 82-87
Author(s):  
Susi R. Puspitadewi ◽  
Lindawati S. Kusdhany ◽  
Sri Lelyati C. Masulili ◽  
Pitu Wulandari ◽  
Hanna B. Iskandar ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Postmenopausal Women ◽  
Alveolar Bone ◽  
Bone Mineralization ◽  
Cross Sectional Study ◽  
Enzyme Linked Immunosorbent Assay ◽  
Blood Collection ◽  
Cross Sectional

Background: Postmenopausal women exhibit reduced bone mineralization, which causes bone resorption, including that of alveolar bone. Parathyroid hormone has been shown to play a role in alveolar bone resorption. Objective: This study aims to analyze relationships between parathyroid hormone and other factors that may contribute to alveolar bone resorption in postmenopausal women. Methods: This cross-sectional study included 82 postmenopausal women aged 50–74 years, who resided in Central and East Jakarta, Indonesia. Subjects' data were obtained through questionnaires, dental examinations, and blood collection for the examination of parathyroid hormone levels by enzyme-linked immunosorbent assay and using panoramic radiography to measure bone resorption. Results: Spearman correlation analysis showed a significant correlation between parathyroid hormone level (p = 0.005) and extent of alveolar bone resorption, but age (p = 0.292), menopausal duration (p = 0.244), and number of missing teeth (p = 0.517) were not significantly correlated with the extent of alveolar bone resorption. Conclusion: Various factors play a role in the mechanism of bone resorption, so knowing the role of each factor is expected to reduce the effects of alveolar bone resorption that occurs in postmenopause. Among the factors investigated in this study, the parathyroid hormone was the sole factor correlated with postmenopausal alveolar bone resorption.

scholarly journals Possible evidence of pregnancy and or famine in an ancient nubian female

2005 ◽  
Vol 80 (1) ◽  
Author(s):  
John Denton ◽  
Jennifer Mann ◽  
Ann Rosalie David
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Physical Exercise ◽  
Bone Tissue ◽  
Calcium Intake ◽  
Nutritional Quality ◽  
Bone Cells ◽  
Mechanical Stresses ◽  
Bone Apposition ◽  
Blood Calcium

A female Nubian femur from the Manchester Mummy Collection exhibits periodic features of bone resorption, bone apposition and then bone resorption as demonstrated by bone histology. Bone is a metabolically active, dynamic, structural tissue whose development and maintenance is influenced by many factors, including nutrition, sunlight, hormonal secretions, and physical exercise. When biochemical or mechanical stresses occur bone cells respond either producing or resorbing bone. When food becomes scarce or of poor nutritional quality, for example in times of famine or flood, malnutrition and concurrent low calcium intake occur. In low blood calcium conditions, parathyroid hormone is released. This stimulates osteoclasts to break down bone tissue. When nutritional state normalises, bone is laid down again and this cycle recurs. Additionally, during pregnancy there is profound resorbtion of the maternal skeleton in order that the foetus may thrive. The condition of the observed bone is consistent with such cyclic events.

Role of parathyroid hormone in mediating nocturnal and age-related increases in bone resorption.

1995 ◽  
Vol 80 (11) ◽  
pp. 3304-3310 ◽  
Author(s):  
G A Ledger ◽  
M F Burritt ◽  
P C Kao ◽  
W M O'Fallon ◽  
B L Riggs ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Age Related
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