Adolescence: How do we increase intestinal calcium absorption to allow for bone mineral mass accumulation?

2007 ◽  
Vol 4 (5) ◽  
pp. 147-157 ◽  
Author(s):  
Steven A Abrams ◽  
Gordon J Strewler
Keyword(s):  
Bone Mineral ◽  
Calcium Absorption ◽  
Intestinal Calcium Absorption ◽  
Bone Mineral Mass ◽  
Mass Accumulation ◽  
Mineral Mass

scholarly journals A Dynamic Model of Calcium Metabolism for Predicting the Effects of Treatments on Bone Mineral Mass in Young Growing Rats (P24-046-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Joanna Hodges ◽  
Meryl Wastney ◽  
Emily Hohman ◽  
Connie Weaver
Keyword(s):  
Bone Mass ◽  
Dynamic Model ◽  
Bone Mineral ◽  
Calcium Metabolism ◽  
Calcium Absorption ◽  
Male Rats ◽  
Total Calcium ◽  
Growing Rats ◽  
Bone Mineral Mass ◽  
Mineral Mass

Abstract Objectives Quantifying the long-term effects of nutritional or drug treatments on bone is challenging due to the delay in time between treatment and changes in bone mass. The objective of this study was to develop a dynamic (non-steady state) mathematical model of calcium metabolism in young growing rats as an analogue for human adolescents and to use that model to predict the effects of treatments on calcium mass in bone. Methods A dynamic model of calcium metabolism was developed using kinetic data collected from Sprague-Dawley male rats (n = 54) dosed intraperitoneally with 50 μCi of 45Ca at 4 wk of age. Total calcium and 45Ca levels measured in serum and 24-h urine samples collected periodically for 45 d after treatment were analyzed by compartmental modeling using WinSAAM software. Concurrently, tracer (45Ca) and tracee (total calcium) models, together called the ‘dynamic model’, were developed. Growth of the rats was modeled using a formula based on body weight. Calcium absorption was decreased by about 50% at wk 6 to account for the reduction in bone mineral accretion in late puberty. During the first 40 d after weaning, the model included a 4-fold decrease in bone resorption and a 20-fold decrease in bone formation, consistent with previous findings of studies conducted in growing rats. Data were fitted by iterative least squares regression analysis. To mimic the effects of dietary and drug interventions during adolescence, the absorption efficiency was manipulated in terms of degree, timing, and duration and the subsequent changes in bone mass were quantified. Results The dynamic model predicted that, if absorption decreased by 25% instead of 50% during growth, the rate of bone accretion would be 32% higher and the bone mineral mass at d 50 would be 24% larger, suggesting that a dietary or drug intervention that minimizes the drop in absorption, would result in a higher bone mineral mass. Conclusions A dynamic model of calcium metabolism during growth was developed and used to predict the effect of interventions on bone mass. These predictions would be tested in future studies. Funding Sources Purdue University Graduate School and Amgen, Inc., Thousand Oaks, CA.

Effects of Low Molecular Weight Heparin and Unfragmented Heparin on Induction of Osteoporosis in Rats

1990 ◽  
Vol 63 (03) ◽  
pp. 505-509 ◽  
Author(s):  
Thomas Mätzsch ◽  
David Bergqvist ◽  
Ulla Hedner ◽  
Bo Nilsson ◽  
Per Østergaar
Keyword(s):  
Molecular Weight ◽  
Bone Mineral ◽  
Low Molecular Weight Heparin ◽  
Zinc Content ◽  
Low Molecular Weight ◽  
Dependent Manner ◽  
Bone Mineral Mass ◽  
Bone Ash ◽  
Dose Dependent ◽  
Mineral Mass

SummaryA comparison between the effect of low molecular weight heparin (LMWH) and unfragmented heparin (UH) on induction of osteoporosis was made in 60 rats treated with either UH (2 IU/ g b w), LMWH in 2 doses (2 Xal U/g or 0.4 Xal U/g) or placebo (saline) for 34 days. Studied variables were: bone mineral mass in femora; fragility of humera; zinc and calcium levels in serum and bone ash and albumin in plasma. A significant reduction in bone mineral mass was found in all heparin-treated rats. There was no difference between UH and LMWH in this respect. The effect was dose-dependent in LMWH-treated animals. The zinc contents in bone ash were decreased in all heparin-treated rats as compared with controls. No recognizable pattern was seen in alterations of zinc or calcium in serum. The fragility of the humera, tested as breaking strength did not differ between treatment groups and controls. In conclusion, if dosed according to similar factor Xa inhibitory activities, LMWH induces osteoporosis to the same extent as UH and in a dose-dependent manner. The zinc content in bone ash was decreased after heparin treatment, irrespective of type of heparin given.

Bone mineral mass consolidation in young British adults

2009 ◽  
Vol 11 (2) ◽  
pp. 264-274 ◽  
Author(s):  
Tessa J. Parsons ◽  
Ann Prentice ◽  
Elisabeth A. Smith ◽  
Tim J. Cole ◽  
Juliet E. Compston
Keyword(s):  
Bone Mineral ◽  
Bone Mineral Mass ◽  
Mineral Mass

scholarly journals New method for assessing bone mineral mass

1996 ◽  
Vol 64 (4) ◽  
pp. 664-664
Author(s):  
M Fukunaga ◽  
M Sakamoto
Keyword(s):  
Bone Mineral ◽  
New Method ◽  
Bone Mineral Mass ◽  
Mineral Mass

Is Bone Mineral Mass Truly Decreased in Teenagers With a First Episode of Forearm Fracture? A Prospective Longitudinal Study

2012 ◽  
Vol 32 (6) ◽  
pp. 579-586 ◽  
Author(s):  
Dimitri Ceroni ◽  
Xavier Martin ◽  
Cécile Delhumeau-Cartier ◽  
René Rizzoli ◽  
André Kaelin ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Bone Mineral ◽  
Forearm Fracture ◽  
First Episode ◽  
Prospective Longitudinal Study ◽  
Bone Mineral Mass ◽  
Prospective Longitudinal ◽  
Mineral Mass

Effects of Cast-Mediated Immobilization on Bone Mineral Mass at Various Sites in Adolescents with Lower-Extremity Fracture

2012 ◽  
Vol 94 (3) ◽  
pp. 208-216 ◽  
Author(s):  
Dimitri Ceroni ◽  
Xavier Martin ◽  
Cécile Delhumeau ◽  
René Rizzoli ◽  
André Kaelin ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Bone Mineral ◽  
Bone Mineral Mass ◽  
Lower Extremity Fracture ◽  
Extremity Fracture ◽  
Mineral Mass
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