Document Detail


Nicotine increases chemoreflex sensitivity to hypoxia in non-smokers.
MedLine Citation:
PMID:  18192843     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
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.
Authors:
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:
Type:  Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of hypertension     Volume:  26     ISSN:  0263-6352     ISO Abbreviation:  J. Hypertens.     Publication Date:  2008 Feb 
Date Detail:
Created Date:  2008-01-14     Completed Date:  2008-04-18     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8306882     Medline TA:  J Hypertens     Country:  England    
Other Details:
Languages:  eng     Pagination:  284-94     Citation Subset:  IM    
Affiliation:
Department of Cardiology, CUB Erasme, Brussels, Belgium. jfxa@skynet.be
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MeSH Terms
Descriptor/Qualifier:
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:
0/Ganglionic Stimulants; 54-11-5/Nicotine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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