Anti-inflammatory and antithrombotic effects of nicotine exposure in oral contraceptive-induced insulin resistance is glucocorticoid-independent
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Date
2016-12-16
Journal Title
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Publisher
Pharmacological Reports
Abstract
Background: Reports showed that estrogen-progestin oral contraceptive (COC) or tobacco
smoking causes increased risk of cardiovascular diseases (CVD) in premenopausal women.
Studies also suggest that nicotine; a major tobacco alkaloid may worsen or improve
atherothrombotic CVD. Altered hemorheology, prothrombotic and pro-inflammatory
biomarkers, have been implicated in the development of atherothrombotic CVD events.
However, the effect of non-smoking nicotine exposure on these biomarkers during COC
treatment is not yet established. We therefore sought to determine the effects of nicotine
exposure during COC treatment on these biomarkers, and also tested the hypothesis that the
nicotine effects would be glucocorticoid-dependent.
Methods: Female Sprague-Dawley rats aged 10 weeks were given (po) vehicle, low-dose
nicotine (0.1 mg/kg) or high-dose nicotine (1.0 mg/kg) with or without COC steroids (5.0
µg/kg ethinylestradiol and 25.0 µg/kg levonorgestrel) daily for 6 weeks.
Results: COC treatment or nicotine exposure led to increased insulin resistance (IR),
hemorheological (blood viscosity, hematocrit and plasma viscosity), prothrombotic
(plasminogen activator inhibitor-1), pro-inflammatory (uric acid, C-reactive protein,
neutrophil/lymphocyte and platelet/lymphocyte ratios) biomarkers and corticosterone.
However, these effects except that on corticosterone were abrogated by nicotine exposure
during COC treatment.
Conclusions: Our study indicates that nicotine- or COC-induced IR may be mediated via
inflammatory/thrombotic pathway. The results imply that nicotine exposure could impact
negatively on atherothrombotic biomarkers in COC non-users, whereas the impact in COC
users could be positive. The results also suggest that the anti-inflammatory, antithrombotic
and blood viscosity-lowering effects of nicotine exposure during COC use is circulating
glucocorticoid-independent.
Description
Keywords
Atherothrombotic CVD, estrogen-progestin oral contraceptive, proinflammatory biomarker, corticosterone
Citation
Olatunji, L.A., Michael, O.S., Adeyanju, O.A., Areola, E.D. & Soladoye, A.O. (2017). Anti-inflammatory and antithrombotic effects of nicotine exposure in oral contraceptive-induced insulin resistance is glucocorticoid-independent. Pharmacological Reports, 69 (3), 512-519, Published by Elsevier. Available online at: Pharmacological Reports | Vol 69, Issue 3, Pages 377-594 (June 2017) | ScienceDirect.com by Elsevier