| Nicotine increases chemoreflex sensitivity to hypoxia in non-smokers. | |
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MedLine Citation:
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PMID: 18192843 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: The peripheral chemoreflex contributes to cardiovascular regulation and represents the first line of defence against hypoxia. The effects of nicotine on chemoreflex regulation in non-smoking humans are unknown. METHOD: We conducted a prospective, randomized, crossover, and placebo-controlled study in 20 male non-smokers to test the hypothesis that nicotine increases chemoreflex sensitivity. The effects of two intakes of 2 mg nicotine tabs and placebo on sympathetic nerve activity to muscle circulation (muscle sympathetic nerve activity; MSNA), minute ventilation (Ve), blood pressure and heart rate were assessed during normoxia, moderate isocapnic hypoxia, hyperoxic hypercapnia and an isometric handgrip in 10 subjects. Maximal end-expiratory apnoeas were performed at baseline and at the end of the fifth minute of hypoxia. In a second experimental setting, we studied the ventilatory response to a more marked isocapnic hypoxia in 10 other volunteers. RESULTS: Mean MSNA and Ve were not modified by nicotine during the 5 min of normoxia or moderate hypoxia. In the presence of nicotine MSNA was related to oxygen desaturation (P < 0.01). The sympathoexcitatory effects of nicotine became especially evident when apnoeas achieved oxygen saturations less than 85% (511 +/- 44% increase in MSNA after the first intake, and 436 +/- 43% increase after the second intake versus 387 +/- 56% and 338 +/- 31% with placebo, respectively, P < 0.05). Nicotine also increased the ventilatory response compared with placebo when oxygen saturation decreased to less than 85% (P < 0.05). CONCLUSION: This is the first study to demonstrate that nicotine increases peripheral chemoreflex sensitivity to large reductions in arterial oxygen content in healthy non-smokers. |
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Authors:
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Jean-François Argacha; Olivier Xhaët; Marko Gujic; Dionysios Adamopoulos; Sofia Beloka; Celine Dreyfuss; Jean-Paul Degaute; Philippe van de Borne |
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Publication Detail:
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Type: Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of hypertension Volume: 26 ISSN: 0263-6352 ISO Abbreviation: J. Hypertens. Publication Date: 2008 Feb |
Date Detail:
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Created Date: 2008-01-14 Completed Date: 2008-04-18 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 8306882 Medline TA: J Hypertens Country: England |
Other Details:
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Languages: eng Pagination: 284-94 Citation Subset: IM |
Affiliation:
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Department of Cardiology, CUB Erasme, Brussels, Belgium. jfxa@skynet.be |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adult Anoxia / physiopathology* Apnea / physiopathology Blood Pressure / drug effects, physiology Carotid Body / drug effects Chemoreceptor Cells / drug effects* Cross-Over Studies Electrocardiography / drug effects Ganglionic Stimulants / pharmacology* Heart Rate / drug effects*, physiology Humans Male Nicotine / pharmacology* Prospective Studies Respiration / drug effects* |
| Chemical | |
Reg. No./Substance:
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0/Ganglionic Stimulants; 54-11-5/Nicotine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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