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Combined effect of chronic hypoxia and in vitro exposure to gas pollutants on airway reactivity

Authors: Etienne, Roux; Michel, Duvert; Roger, Marthan;

Combined effect of chronic hypoxia and in vitro exposure to gas pollutants on airway reactivity

Abstract

This study investigated the interaction between exposure to air pollutants and chronic hypoxia (CH). We used a hypobaric chamber (14 days at barometric pressure 380 mmHg) to produce CH in rats. Exposure to various doses of acrolein or ozone did not modify the mechanical response to cholinergic agonists. Exposure to 3 μM/min acrolein did not alter epithelium-free trachea responsiveness. In contrast, direct exposure of freshly isolated myocytes to 2 and 3 μM/min acrolein enhanced the amplitude of the first intracellular [Ca2+] rise in response to 0.1 μM ACh and the calcium oscillation frequency in response to 10 μM ACh. CH alone did not alter smooth muscle cross-sectional area (SMA) or epithelium-plus-submucosa thickness. CH decreased maximal contractile response (maximal force normalized to SMA) but increased sensitivity (pEC50) to cholinergic agonists. We conclude that unlike in normoxic rats, exposure to air pollutants does not induce airway hyperresponsiveness in CH rats, although it increased calcium signaling. These results cannot be explained by change in smooth muscle accessibility, but may be linked to the effect of CH on calcium-contraction coupling.

Keywords

Male, Air Pollutants, Osmolar Concentration, Muscle, Smooth, Intracellular Membranes, Cholinergic Agonists, Acetylcholine, Rats, Trachea, Oxidants, Photochemical, Ozone, Chronic Disease, Animals, Calcium, Carbachol, Gases, Acrolein, Rats, Wistar, Hypoxia

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Powered by OpenAIRE graph
citations
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
16
Average
Average
Top 10%