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Published on: September 10, 2014
Acute High-Altitude Exposure Increases Transcription of Tricarboxylic Acid Cycle Enzymes in Human Duodenal Biopsies
Patrick-Pascal Strunz1, Raphael N Vuille-Dit-Bille2, Heiko Fruehauf3
1Rheumatology/Clinical Immunology, Department of Medicine II, University Hospital Wurzburg, Wuerzburg, Germany.
Abstract:
Strunz, Patrick-Pascal, Raphael N. Vuille-dit-Bille, Heiko Fruehauf, Mark Fox, Andreas Geier, Marco Maggiorini, Max Gassmann, Thomas A. Lutz, and Oliver Goetze. Acute high-altitude exposure increases transcription of tricarboxylic acid cycle enzymes in human duodenal biopsies. High Alt Med Biol. 27:184-188, 2026.
Background:
A recent study of our group quantifying 13C-octanoate metabolism in HA (Capanna Margherita [MG]/4,559 m) showed that acute HA exposure might lead to an increase of the lipolytic and CO2-producing pathways.
Objective:
To further test this hypothesis, we investigated intestinal biopsies from the same participants from simultaneously performed endoscopy studies for changes of mRNA-expression levels of the beta-oxidation enzymes and the decarboxylating tricarboxylic acid cycle (TCA) enzymes.
Methods:
Duodenal biopsies of 16 subjects exposed to HA were sampled via gastro-duodenoscopy at Zurich (baseline ZH, 490 m), on day 2 (MG2) and on day 4 at HA (MG4). After mRNA extraction, quantitative real-time polymerase chain reaction was performed to assess mRNAs expression of TCA cycle enzymes as well as beta-oxidation enzymes.
Results:
Aconitase mRNA levels increased early (MG2 vs. ZH, p < 0.05) and were still higher at day 4 compared with ZH (MG4 vs. ZH, p < 0.05). Isocitrate dehydrogenase (DH) levels increased with time spent at 4,559 m (MG4 vs. ZH, p < 0.01). The remaining TCA cycle and beta-oxidation enzymes investigated tended to higher values at HA but without reaching significance.
Conclusion:
We conclude that acute exposure to HA leads to increased transcription of aconitase and isocitrate DH in the duodenal mucosa due to hypobaric hypoxia exposure.
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