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Interactive effects of maternal cigarette smoke, heat stress, hypoxia, and lipopolysaccharide on neonatal cardiorespiratory and cytokine responses
- Source :
- American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 311:R1113-R1124
- Publication Year :
- 2016
- Publisher :
- American Physiological Society, 2016.
-
Abstract
- Maternal cigarette smoke (CS) exposure exhibits a strong epidemiological association with Sudden Infant Death Syndrome, but other environmental stressors, including infection, hyperthermia, and hypoxia, have also been postulated as important risk factors. This study examines whether maternal CS exposure causes maladaptations within homeostatic control networks by influencing the response to lipopolysaccharide, heat stress, and/or hypoxia in neonatal rats. Pregnant dams were exposed to CS or parallel sham treatments daily for the length of gestation. Offspring were studied at postnatal days 6–8 at ambient temperatures (Ta) of 33°C or 38°C. Within each group, rats were allocated to control, saline, or LPS (200 µg/kg) treatments. Cardiorespiratory patterns were examined using head-out plethysmography and ECG surface electrodes during normoxia and hypoxia (10% O2). Serum cytokine concentrations were quantified from samples taken at the end of each experiment. Our results suggest maternal CS exposure does not alter minute ventilation (V̇e) or heart rate (HR) response to infection or high temperature, but independently increases apnea frequency. CS also primes the inflammatory system to elicit a stronger cytokine response to bacterial insult. High Ta independently depresses V̇e but augments the hypoxia-induced increase in V̇e. Moreover, higher Ta increases HR during normoxia and hypoxia, and in the presence of an immune challenge, increases HR during normoxia, and reduces the increase normally associated with hypoxia. Thus, while most environmental risk factors increase the burden on the cardiorespiratory system in early life, hyperthermia and infection blunt the normal HR response to hypoxia, and gestational CS independently destabilizes breathing by increasing apneas.
- Subjects :
- Lipopolysaccharides
Male
Hyperthermia
Lipopolysaccharide
Physiology
medicine.medical_treatment
Inflammation
Biology
Rats, Sprague-Dawley
03 medical and health sciences
chemistry.chemical_compound
0302 clinical medicine
Heart Rate
Pregnancy
030225 pediatrics
Physiology (medical)
medicine
Animals
Hypoxia
Respiration
Apnea
Cardiorespiratory fitness
Hypoxia (medical)
Sudden infant death syndrome
medicine.disease
Cytokine
Animals, Newborn
chemistry
Maternal Exposure
Prenatal Exposure Delayed Effects
Immunology
Cytokines
Female
Tobacco Smoke Pollution
medicine.symptom
Pulmonary Ventilation
Heat-Shock Response
030217 neurology & neurosurgery
Subjects
Details
- ISSN :
- 15221490 and 03636119
- Volume :
- 311
- Database :
- OpenAIRE
- Journal :
- American Journal of Physiology-Regulatory, Integrative and Comparative Physiology
- Accession number :
- edsair.doi.dedup.....8e12407b495b72f25d77b20b71466fa7