Model of plasma calcium regulation: system oscillations induced by growth

Hurwitz, S.; Fishman, Svetlana; Talpaz, Hovav

doi:10.1152/ajpregu.1987.252.6.r1173

Cited by 13 publications

(10 citation statements)

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“…ALP (Eleniste, Huang, Wayakanon, Largura, & Bruzzaniti, ) and OCN (Lenders et al, ) are markers of osteoblast activity. ALP hydrolyses inorganic pyrophosphates that inhibit bone mineralization, improves osteoblast activity, increases bone mass and enhances bone metabolism (Hurwitz, Fishman, & Talpaz, ). When the ratio of Ca/AP in the diet cannot meet the needs of the body, the secretion of PTH increases, which promotes the proliferation of osteoblasts.…”

Section: Discussionmentioning

confidence: 99%

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Effects of dietary calcium to available phosphorus ratios on bone metabolism and osteoclast activity of the OPG /RANK/RANKL signalling pathway in piglets

Zhao

Sun

2019

Animal Physiology Nutrition

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Hydroxyapatite, a mineral form of calcium (Ca) and phosphorus (P) that gives bones their rigidity, is the major and essential component of bones and teeth in the human and animal body. A suitable ratio of Ca and P is vital for bone growth. The aim of this study was to explore the effects of dietary calcium to available phosphorus ratios (Ca/AP) on bone metabolism and osteoclast activity of the osteoprotegerin (OPG)/receptor activator of nuclear factor kappa B ligand (RANKL) signalling pathway in piglets. At days 15 and 29, the piglets were assessed for growth performance, blood indicators, cytokines and the OPG/RANK/RANKL signalling pathway. Our results showed that piglets fed a dietary Ca/AP ratio of 2:1 increases growth performance and regulates blood indicators and cytokines (parathyroid hormone (PTH), calcitonin (CT), vitamin D3 (VD3), insulin‐like growth factor‐1 (IGF‐1), transforming growth factor‐β (TGF‐β), interleukin‐1 (IL‐1), interleukin‐6 (IL‐6), carboxyterminal propeptide of type I procollagen (PICP), tartrate‐resistant acid phosphatase (TRACP), alkaline phosphatase (ALP) and osteocalcin (OCN) content). We also demonstrated that this ratio affects hormone secretion and further bone metabolism through the OPG/RANK/RANKL signalling pathway of osteoclasts. These results indicate that a suitable dietary Ca/AP ratio is vital for bone growth and reduce the incidence of bone diseases such as osteoporosis, providing a practical basis for the raising of piglets.

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Section: Discussionmentioning

confidence: 99%

“…ALP hydrolyses inorganic pyrophosphates that inhibit bone mineralization, improves osteoblast activity, increases bone mass and enhances bone metabolism (Hurwitz, Fishman, & Talpaz, 1987).…”

Section: Discussionmentioning

confidence: 99%

Effects of dietary calcium to available phosphorus ratios on bone metabolism and osteoclast activity of the OPG /RANK/RANKL signalling pathway in piglets

Zhao

Sun

2019

Animal Physiology Nutrition

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“…Particularly useful in the context of the model presented here were analytic descriptions of the response of the parathyroid gland to the ECC calcium concentration (7,40). We constructed our model along the lines of those developed for the chick by Hurwitz and co-workers (41)(42)(43).…”

Section: Discussionmentioning

confidence: 99%

A Minimal Mathematical Model of Calcium Homeostasis

Raposo¹,

Sobrinho²,

Ferreira

2002

The Journal of Clinical Endocrinology & Metabolism

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A mathematical model of calcium homeostasis is presented in which the controlling factors are the plasma concentrations of calcium, PTH, and calcitriol, and the effector organs are the parathyroids, bone, kidney, and intestine. Other factors can be added as the need arises. The model is aimed at simulating what happens in a single individual, but its parameters and variables were adjusted to the corresponding published average values. Simulations of published observations in humans undergoing the infusion of calcium or its chelators are presented. With a single exception, these simulations provided a good fit to the data. The response of the system to extrinsic perturbations was characterized by simulating chronic infusions of calcium, PTH, and calcitriol. Finally, the steady state response to perturbations in some of its parameters (the secretory mass of the parathyroids and the affinity and/or sensitivity of the calcium, PTH, and calcitriol receptors) and to renal failure were also investigated in an attempt to analyze the pathogenesis of clinical hypo- or hypercalcemias. In its present form the model cannot be used to base clinical decisions in individual cases. However, it requires modest computational resources, and clinicians with a modest mathematical background can manipulate it. It is a useful tool for the analysis of general mechanisms of the diseases of calcium metabolism and for the design of clinical experiments aimed at characterizing these diseases. The model can also be the core of future autoadaptive extensions to be used in individual patients.

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“…The model is shown schematically in Figure 1. As detailed previously [Hurwitz et al, 1987a,bl, the model includes a series of differential equations describing the contributions of intestinal absorption, kidney, and bone to plasma calcium. These major control systems are regulated by PTH and 1,25[OH12D3, the concentration of which is the integral of their formation and decay rates.…”

Section: Materials and Methods The Simulation Algorithmmentioning

confidence: 99%

Oscillatory behavior of control‐systems of calcium homeostasis in chickens

Hurwitz¹,

Miller²,

Norman³

1994

J of Cellular Biochemistry

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Computer simulation of calcium homeostasis in chicks predicted an oscillatory behavior of bone calcium flow and kidney 25-hydroxyvitamin D3-1-hydroxylase with a periodicity of 56 h and a 9 h phase difference between the two signals. In growing chickens subjected to a light: dark cycle of 22:2 h, and intravenously dosed with 45Ca, the temporal changes in plasma 45Ca could be described by an exponential decline with superimposed diurnal oscillations. The activity of the renal 25-hydroxyvitamin D3-1-hydroxylase in chicks subjected to a 12:12 h light: dark cycle ALSO followed diurnal oscillations, with a nadir at the beginning of the light period and a peak 12 h later. The production of 1,25-dihydroxyvitamin D3 by primary cultures of chicken kidney cells oscillated with a periodicity of 5.6 h or shorter. It is suggested that despite the differences in phase and periodicity between the simulation predictions and actual results, the oscillations in both 1-hydroxylase and bone calcium flow could be coupled through the hormonal systems involved in regulation of plasma calcium.

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Model of plasma calcium regulation: system oscillations induced by growth

Cited by 13 publications

References 0 publications

Effects of dietary calcium to available phosphorus ratios on bone metabolism and osteoclast activity of the OPG /RANK/RANKL signalling pathway in piglets

Effects of dietary calcium to available phosphorus ratios on bone metabolism and osteoclast activity of the OPG /RANK/RANKL signalling pathway in piglets

A Minimal Mathematical Model of Calcium Homeostasis

Oscillatory behavior of control‐systems of calcium homeostasis in chickens

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