Nicotine Induces Maternal and Fetal Inflammatory Responses Which Predispose Intrauterine Infection Risk in a Rat Model
| Autor: | Leticia Reyes, Maria von Chamier, Linda F. Hayward, Mary Bomberger Brown |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty Nicotine Amniotic fluid medicine.medical_treatment Placenta Original Investigations Context (language use) Rats Sprague-Dawley 03 medical and health sciences 0302 clinical medicine Pregnancy 030225 pediatrics Internal medicine medicine AcademicSubjects/SOC02541 Animals Fetus business.industry Public Health Environmental and Occupational Health Nicotine replacement therapy medicine.disease Amniotic Fluid Tobacco Use Cessation Devices Rats 030104 developmental biology Endocrinology Gestation Smoking cessation Female Smoking Cessation business AcademicSubjects/MED00010 medicine.drug |
| Zdroj: | Nicotine & Tobacco Research |
| ISSN: | 1469-994X 1462-2203 |
| Popis: | Introduction Both smoking and infection adversely impact pregnancy. Previously, our group identified in a rodent model that 6 mg/kg/d nicotine increased the risk of fetal infection at gestation day (GD) 18. Here, we investigate lower nicotine doses. Methods Pregnant Sprague-Dawley rats received nicotine infusion at 0, 1, or 3 mg/kg/d (no, low-, and mid-dose nicotine, respectively) from GD 6, with intravenous inoculation with Mycoplasma pulmonis (MP) at 107 CFU (N = 20) or sterile broth (sham) (N = 11) on GD 14. Uterus and fetuses were retrieved on GD 18 for MP culture and histopathologic evaluation of maternal and fetal inflammatory responses (MIR and FIR). Results At 1 mg/kg/d nicotine, MP colonization rates were decreased, from 100% (9 of 9) to 40% (2 of 5) of MP-inoculated dams (p = .03), and 59% (66 of 111) to 39% (24 of 62) of fetuses (p = .01), versus no nicotine. Low-dose nicotine resulted in increased MIR and FIR in the sham-inoculated group; in the MP-inoculated group, this resulted in reduced relative risk (RR) for placental colonization (RR, 95% CI with high MIR = 0.14, 0.02 to 0.65; FIR = 0.38, 0.12 to 0.93). In contrast, 3 mg/kg/d nicotine treatment did not alter colonization rates; furthermore, FIR was completely suppressed, even in the face of placental or amniotic fluid colonization. Conclusion The 1 mg/kg/d nicotine dose decreased risk of intrauterine infection, with increased MIR and FIR. The 3 mg/kg/d nicotine dose inhibited FIR, and increased risk for intrauterine infection. Nicotine alterations of the intrauterine environment were markedly dose-dependent. Implications Nicotine exposure alters intrauterine infection and inflammation in a dose-dependent manner, potentially impacting fetal development and programming. Previous work in a rodent model showed that high-dose nicotine (6 mg/kg/d) exposure exacerbated intrauterine infection during pregnancy. The current study found that low-dose nicotine (1 mg/kg/d) exposure reduced colonization of placenta and amniotic fluid; this decrease was associated with increased intrauterine inflammation. Exposure to mid-dose nicotine (3 mg/kg/d) suppressed fetal inflammation. Elucidation of underlying mechanisms of these phenomena will inform public health and clinical care decisions, particularly in the context of risk assessment of nicotine replacement therapy during pregnancy for smoking cessation. |
| Databáze: | OpenAIRE |
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