Calcium Regulating Hormones after Oral and Intravenous Calcium Administration

Herfarth, Klaus; Drechsler, S.; Imhoff, Walter; Schlander, Michael; Engelbach, M.; Maier, Andreas; Schmidt‐Gayk, H.

doi:10.1515/cclm.1992.30.12.815

Cited by 10 publications

(6 citation statements)

References 29 publications

(21 reference statements)

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“…In addition, selfreported calcium supplementation may not be accurately reflected by serum calcium levels. Previous studies [28][29][30][31] have found that oral calcium administration is associated with increases in plasma ionized calcium and urinary calcium and decreases in plasma parathyroid hormone. However, there is a linear decrease in intestinal calcium absorption efficiency with increasing age, particularly after 40 years of age.…”

Section: Discussionmentioning

confidence: 97%

Self-reported Calcium Supplementation and Age-Related Macular Degeneration

et al. 2015

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Section: Discussionmentioning

confidence: 97%

Self-reported Calcium Supplementation and Age-Related Macular Degeneration

et al. 2015

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“…[17][18][19][20] In this study, the feedback activity was investigated after i.v. [17][18][19][20] In this study, the feedback activity was investigated after i.v.…”

Section: Discussionmentioning

confidence: 99%

“…[17][18][19][20] As theˆnal purpose of this study is concerned, it is not necessary to construct a complicated model including several factors for the regulation system because of an increase in information required for the modeling. [17][18][19][20] As theˆnal purpose of this study is concerned, it is not necessary to construct a complicated model including several factors for the regulation system because of an increase in information required for the modeling.…”

Section: Theoreticalmentioning

confidence: 99%

Estimation of Bioavailability of Salmon Calcitonin from the Hypocalcemic Effect in Rats (I): Pharmacokinetic-Pharmacodynamic Modeling Based on the Endogenous Ca Regulatory System

Miyazaki

Nakade

Iwanaga

et al. 2003

Drug Metabolism and Pharmacokinetics

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The hypocalcemic effect of salmon calcitonin (sCT) after intravenous administration was explained on the basis of an integrated pharmacokinetic-pharmacodynamic (PK-PD) model with the endogenous Ca regulatory system in the rat. The pharmacokinetics of sCT described by a conventional two-compartment model showed the extremely rapid elimination of sCT from plasma (MRT; 6.86 min). The hypocalcemic effect of sCT reached a peak from 0.5 to 1.5 hrs after administration, and the peak time tended to prolong with increasing doses. This delay in pharmacological effect of sCT against plasma concentration may be a result of a summation of multiple actions of the endogenous Ca regulatory system including feedback control. The plasma Ca regulation system in the rat was investigated by i.v. bolus administration of calcium gluconate and/or endogenous (rat) calcitonin (rCT). Since non-linearity in the relationship between Ca and rCT concentrations in plasma was observed, we assumed that rCT was secreted in accordance with the plasma Ca level via an exponential function. The pharmacokinetics of rCT was represented as a linear one-compartment model. To link the rCT level with plasma Ca level, an additional effect compartment was required to explain the delay in onset and decline of the pharmacological effect. This Ca regulation model explained the observed Ca and rCT profiles in plasma after administration of Ca and/or rCT. The plasma Ca levels after administration of sCT could be well described by the present integrated model. This suggested the potential for prediction of plasma sCT concentration only from the hypocalcemic effect after extravascular administration of sCT, using this PK-PD model.

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“…An acute oral calcium load has been shown to inhibit serum PTH and bone resorption (Woo et al, 1991;Reginster et al, 1993;McKane et al, 1996;Rubinacci et al, 1996). The acute suppressive effect of an oral calcium dose of 1000 mg on both serum PTH secretion (Herfarth et al, 1992;Horowitz et al, 1994;Kärkkäinen et al, 1997) and biochemical markers of bone resorption such as CTX (Zikan et al, 2001) have been studied. The above authors showed that an acute calcium load of 1000 mg suppresses PTH and bone resorption to a similar degree in young and late postmenopausal women with normal calcium absorption.…”

Section: Introductionmentioning

confidence: 99%

Effect of acute oral calcium load on serum PTH and bone resorption in young healthy subjects: an overnight study

Sadideen

Swaminathan

2004

Eur J Clin Nutr

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Objective: To investigate the effects of a 400 mg acute oral calcium dose on PTH and bone resorption markers in a young, healthy population. Design: Fasting serum parathyroid hormone (PTH), C-telopeptides (CTX), total calcium (Ca), albumin and urinary calcium/ creatinine ratio (uCa/Cr) were measured on two separate days: one before and the other 10 h after oral administration of 400 mg calcium. Serum 25-hydroxy vitamin D (25-OHD) status was assessed at baseline. Dietary calcium intake was assessed using a food frequency questionnaire (FFQ). Subjects: A total of 32 healthy, young adults (17 female, 15 male; mean7s.e.m. age: 2171 y) took part in this study. Their mean (s.e.m.) calcium intake was 1125 (756) mg/day. Intervention: Effervescent Sandocal s 400 tablets dissolved in water. Results: After the calcium challenge, mean Ca and uCa/Cr ratio increased significantly, and both PTH and CTX concentrations were significantly lower. Multiple regression analysis showed no relationship between the response to the 400 mg load and previous dietary calcium intake (as assessed by FFQ) or serum 25-OHD. Conclusion: We have shown that in a young, healthy population, 400 mg oral calcium can inhibit bone resorption (as measured by serum CTX) and PTH, and this appears to be independent of previous dietary calcium intake and vitamin D status. Sponsorship: None.

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Calcium Regulating Hormones after Oral and Intravenous Calcium Administration

Cited by 10 publications

References 29 publications

Self-reported Calcium Supplementation and Age-Related Macular Degeneration

Self-reported Calcium Supplementation and Age-Related Macular Degeneration

Estimation of Bioavailability of Salmon Calcitonin from the Hypocalcemic Effect in Rats (I): Pharmacokinetic-Pharmacodynamic Modeling Based on the Endogenous Ca Regulatory System

Effect of acute oral calcium load on serum PTH and bone resorption in young healthy subjects: an overnight study

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