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Essential Metal Uptake in Gram-negative Bacteria: X-ray Fluorescence, Radioisotopes, and Cell Fractionation
Published on: February 1, 2018
Gastrointestinal function, divalent metal transporter-1 expression and intestinal iron absorption
P S Oates1, D Trinder, E H Morgan
1Department of Physiology, The University of Western Australia, Nedlands, Australia. poates@cyllene.uwa.edu.au
Pflugers Archiv : European Journal of Physiology
|August 23, 2000
Summary
Iron absorption relies on divalent metal transporter-1 (DMT1). Its functional activity is regulated by de novo synthesis, which is controlled by enterocyte iron levels post-transcriptionally.
Area of Science:
- Cell Biology
- Gastroenterology
- Nutritional Science
Background:
- Iron absorption is a crucial physiological process involving specific transporters.
- Divalent metal transporter-1 (DMT1) is implicated in iron uptake across the enterocyte microvillus membrane.
- DMT1's localization and regulation are key to maintaining iron homeostasis.
Purpose of the Study:
- To investigate the role of DMT1 in iron absorption regulation.
- To examine the relationship between DMT1 expression, localization, and iron absorption efficiency.
- To determine how enterocyte iron levels influence DMT1 activity.
Main Methods:
- In vivo gut sac experiments were used to measure iron absorption processes.
- Animals were subjected to fasting and iron gavage protocols.
- DMT1 staining intensity and gene expression (mRNA) in the duodenum were analyzed and correlated with absorption rates.
Main Results:
- Fasting significantly increased iron absorption, while iron gavage decreased it.
- These changes were primarily attributed to alterations in the iron uptake phase, not the transfer phase.
- A strong correlation was observed between reduced iron absorption and decreased DMT1 staining and mRNA expression at the microvillus membrane.
Conclusions:
- DMT1 functional activity is dependent on de novo synthesis.
- Enterocyte iron levels regulate DMT1 synthesis post-transcriptionally.
- The observed decrease in DMT1 at the microvillus membrane appears to be due to protein degradation rather than translocation from the cytoplasm.
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