Calmodulin may mediate 1,25‐dihydroxyvitamin D‐stimulated intestinal calcium transport

Bikle, Daniel D.; Munson, Scott; Chafouleas, James G.

doi:10.1016/0014-5793(84)81071-6

Cited by 40 publications

(12 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this way, the unhindered entrance of luminal Ca down its steep electropotential gradient into the cell could be controlled, protecting the cell from the toxic effects of this element. The nature of the Ca-binding components subjacent to the microvillar membrane is not known, but cytoskeletal elements and Ca-binding proteins, including calmodulin (21), are likely candidates.…”

mentioning

confidence: 99%

Ion microscopic imaging of calcium transport in the intestinal tissue of vitamin D-deficient and vitamin D-replete chickens: a 44Ca stable isotope study.

Chandra

Fullmer

Smith

et al. 1990

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The intestinal absorption of calcium includes at least three definable steps: transfer across the microvillar membrane, movement through the cytosolic compartment, and energy-dependent extrusion into the lamina propria. Tracing the movement of calcium through the epithelium has been hampered by lack of suitable techniques and, in this study, advantage was taken of ion microscopy in conjunction with cryosectioning and use of the stable isotope "Ca to visualize calcium in transit during the absorptive process. The effect of vitamin D, required for optimal calcium absorption, was investigated. Twenty millimolar 44Ca was injected into the duodenal lumen in situ of vitamin D-deficient and vitamin D-replete chickens. At 2.5, 5.0, and 20.0 min after injection, duodenal tissue was obtained and processed for ion microscopic imaging. At 2.5 min, 44Ca was seen to be concentrated in the region subjacent to the microvillar membrane in tissue from both groups. At 5.0 and 20.0 min, a similar pattern of localization was evident in D-deficient tissues. In D-replete tissues, the distribution of 44Ca became more homogenous, indicating that vitamin D increased the rate of transfer of Ca2" from the apical to the basolateral membrane, a function previously ascribed to the vitamin D-induced calcium-binding protein (28-kDa calbindin-D). Quantitative aspects of the calcium absorptive process were determined in parallel experiments with the radionuclide 47Ca. Complementary information on the localization of the naturally occurring isotopes of calcium (40Ca) and potassium (39K) is also described.The past 20 years have been marked by a growing recognition of the important role of calcium (Ca) as a second messenger, involved in the mediation of a diverse array of cellular functions (1). As a major component of bones and teeth, large amounts of Ca are required for their formation. The only source of Ca to meet these essential functions is ultimately the diet, and mechanisms have evolved to assure an adequate and proper transfer of dietary Ca across the intestine. Special accommodations must be made by the intestinal epithelial cells to transport the large quantities of Ca and, at the same time, assure that the intracellular free Ca2+ concentrations are maintained at levels that are nontoxic and appropriate for normal cell function.A complete understanding of the Ca absorption process and the role of vitamin D thereon, despite considerable effort, is still lacking. One aspect that requires clarification is the path taken by Ca during its transport across epithelia. In the present study, we have visualized this transport by using the stable isotope "Ca as the absorbed species in combination with the technique of ion microscopy (2-4). The ion microscope, based on secondary ion mass spectrometry, is a direct imaging mass spectrometer. The instrument can discriminate isotopes based on their mass-to-charge ratio and, therefore, allows imaging of isotopic gradients in relation to tissue morphology with a spatial resolution of 0O.5 pum. Beca...

show abstract

mentioning

confidence: 99%

Ion microscopic imaging of calcium transport in the intestinal tissue of vitamin D-deficient and vitamin D-replete chickens: a 44Ca stable isotope study.

Chandra

Fullmer

Smith

et al. 1990

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Thomasset et al 34 reported an absence of a significant effect of calcitriol on calmodulin as opposed to calbindin-D9K. In chick duodenal epithelial cells, Bikle et al 40 reported an increase at the brush border level and Long et al 41 an increase at the basolateral membrane. In both cases, there were no changes in total cellular calmodulin content.…”

Section: Discussionmentioning

confidence: 99%

In vivo effect of calcitriol on calcium transport and calcium binding proteins in the spontaneously hypertensive rat.

Roullet

Martin

et al. 1994

Hypertension

View full text Add to dashboard Cite

show abstract

“…The changes in the lipid content of the brush border membrane paralleled increases in calcium uptake, even in the presence of inhibitors of protein synthesis. Bikle et al 36 studied chick small intestine brush border membrane vesicles and showed a 1,25(OHh vitD 3 stimulated increase in the calmodulin content of the brush border membrane which paralleled an increase in calcium uptake. Our laboratory has undertaken several in vitro studies related to intestinal calcium transport in IH patients.…”

Section: Disturbance Of Vitamin D Metabolismmentioning

confidence: 97%

Pathogenesis of idiopathic hypercalciuria: A review

Vosburgh

Peters

1987

J R Soc Med

View full text Add to dashboard Cite

Calmodulin may mediate 1,25‐dihydroxyvitamin D‐stimulated intestinal calcium transport

Cited by 40 publications

References 10 publications

Ion microscopic imaging of calcium transport in the intestinal tissue of vitamin D-deficient and vitamin D-replete chickens: a 44Ca stable isotope study.

Ion microscopic imaging of calcium transport in the intestinal tissue of vitamin D-deficient and vitamin D-replete chickens: a 44Ca stable isotope study.

In vivo effect of calcitriol on calcium transport and calcium binding proteins in the spontaneously hypertensive rat.

Pathogenesis of idiopathic hypercalciuria: A review

Contact Info

Product

Resources

About