Active transport of calcium by the small intestine of the rat

Schachter, David; Dowdle, Eugene B.; Schenker, Harris

doi:10.1152/ajplegacy.1960.198.2.263

Cited by 207 publications

(60 citation statements)

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“…Net absorption of calcium from the mucosal medium was observed at all concentrations tested, and increased directly with initial calcium concentration. Transfer to the serosal medium remained constant at concentrations in the medium of 0.8 /Amole/ml and greater, and as shown previously (28,33), the transfer to the serosal medium is rate limited. Cortisone treatment decreased calcium transport at all concentrations of calcium, and the effect Duodenal gut sacs from each of five control and five cortisonetreated animals were tested at each concentration of calcium.…”

Section: Methodssupporting

confidence: 85%

Effect of cortisone treatment on the active transport of calcium by the small intestine

Kimberg¹,

Baerg²,

Gershon³

et al. 1971

J. Clin. Invest.

260

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A B S T R A C T It is generally recognized that glucocorticoid administration may diminish calcium absorption in vivo as well as the active transport of calcium by the intestine in vitro. Recent studies by others have emphasized the possibility of an alteration in the metabolism of vitamin D to 25-hydroxycholecalciferol in accounting for the steroid effects on calcium absorption. The results obtained in the present studies fail to support this hypothesis.The present studies confirm that the administration of cortisone or other glucocorticoids to the rat interferes with the active transport of calcium by duodenal gut sacs in vitro. This abnormality is not due to an alteration in the permeability of the intestine to calcium, and it cannot be corrected by the administration of either massive doses of vitamin D3 or modest doses of 25-hydroxycholecalciferol. Experiments concerned with the effects of cortisone on the level of the vitamin D-dependent duodenal calcium-binding protein, the amount of bioassayable vitamin D activity in the mucosa, and the distribution and metabolism of 'H-vitamin D3, did not provide evidence in favor of a hormone-related defect in either the localization of vitamin D or its metabolism to 25-hydroxycholecalciferol. Alterations in the transport of iron and D-galactose, not dependent on vitamin D, suggest that cortisone treatment may be responsible for more than a simple antagonism to the effects of vitamin D.The results of the present studies indicate that cortisone administration affects the cellular mechanisms mediating calcium transport in a manner that is opposite to the

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Section: Methodssupporting

confidence: 85%

Effect of cortisone treatment on the active transport of calcium by the small intestine

Kimberg¹,

Baerg²,

Gershon³

et al. 1971

J. Clin. Invest.

260

View full text Add to dashboard Cite

show abstract

“…Most of the Ca in food is present in complexes with other dietary constituents, and therefore, the food must be broken down to release Ca in a soluble and ionized form before absorption. 6 Ionized Ca is absorbed from the duodenum and the proximal part of the jejunum. In our study, the serum Ca levels were significantly reduced in the RGBI compared with the control group.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the effects of gastrectomy on the development of metabolic bone disease

Higashi

Fujimura

Oyama

et al. 2017

Journal of Surgical Research

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and (4) total gastrectomy with Roux-en-Y reconstruction (TGRY group). In all groups, body weight, serum biochemistry (total protein, albumin, calcium, phosphorus, tartrateresistant acid phosphatase, and bone alkaline phosphatase), bone density, and bone breaking strength were measured.Results: Body weights and serum calcium levels were significantly lower in the three operation groups compared with the control group. Bone density was significantly lower in the PSRY and TGRY groups compared with the control group. Bone breaking strength was significantly lower in the three operation groups compared with the control group.Conclusions: Surgical methods led to metabolic bone disease. However, exclusion of the duodenum from food passage had major influence to reduction in bone density and breaking strength. A stomach-preserving procedure and physiological reconstruction which enable food passage through duodenum and proximal jejunum contribute to mitigation of metabolic bone disease. ª

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“…540 CALCIUM FRACI10NS [Ca] It was first demonstrated by McLean and Hastings (1934, J935) in their classical work on the contraction of frog heart muscle that the "free" or "ionised" concentration of calcium is the physiologically active form of that element. Since then evidence has accumulated to support this hypothesis from work on the intestinal absorption of calcium (Schachter et al, 1960), the renal tubular reabsorption of calcium (Walser, 1961a), the stimulation of the parathyroid glands (Sherwood et al, 1966;Chen et al, 1974), the relationship between blood and bone calcium (Rodan et al, 1967), plasma calcium hornoeostasis (Parfitt, 1969), and the activation of cells by various hormones (Rasmussen, 1972). Typical values for the various calcium fractions (i.e, ionised, proteinbound, and complexed) in some body fluids are shown in Table 1.…”

Section: Methodsmentioning

confidence: 99%

Measurement of Ionised Calcium in Body Fluids—A Review

Robertson

1976

Ann Clin Biochem

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This paper reviews the techniques available to the clinical biochemist for measuring ionised calcium concentrations in biological fluids with particular reference to serum. At present ionised calcium may be measured colorimetrically, using tetramethyl murexide, or potentiometrically, using a calcium ion-selective electrode. These techniques compare favourably in terms of precision with existing methods for measuring total calcium. Advantages of measuring ionised calcium in preference to total calcium are ( a) that there is no effect of venous occlusion or change of posture on the ionised fraction of the effect on total calcium, ( b) that ionised calcium is the physiologically active form of the element, and ( c) that the ionised calcium concentration is a more reliable indicator of the calcium status of patients in certain clinical conditions. The main problem in the measurement of ionised calcium is the marked dependence of the ionised fraction on the pH of the sample. Extreme care must be taken to avoid loss of CO2 or build-up of acid during the handling of the blood sample.

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Active transport of calcium by the small intestine of the rat

Cited by 207 publications

References 0 publications

Effect of cortisone treatment on the active transport of calcium by the small intestine

Effect of cortisone treatment on the active transport of calcium by the small intestine

Evaluation of the effects of gastrectomy on the development of metabolic bone disease

Measurement of Ionised Calcium in Body Fluids—A Review

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