title: Prenatal nicotine exposure in rhesus monkeys compromises development of brainstem and cardiac monoamine pathways involved in perinatal adaptation and sudden infant death syndrome: amelioration by vitamin C.
abstract: Maternal smoking during pregnancy greatly enhances perinatal morbidity/mortality and is the major risk factor for Sudden Infant Death Syndrome (SIDS). Studies in developing rodents indicate that nicotine is a neuroteratogen that targets monoamine pathways involved in the responses to hypoxia that are in turn, hypothesized to contribute to these adverse events. We administered nicotine to pregnant Rhesus monkeys from gestational day 30 through 160 by continuous infusion, achieving maternal plasma levels comparable to those in smokers; we examined neurochemical parameters immediately after Cesarean delivery at the end of the exposure period. Nicotine evoked elevations in brainstem serotonin levels and serotonin turnover, indicating hyperactivity of these pathways. The same treatment evoked a deficit in cardiac norepinephrine levels. Both effects were offset by coadministration of the antioxidant, Vitamin C. Brainstem serotonin hyperinnervation is a hallmark of SIDS, and the hyperactivity seen here can also account for the downregulation of serotonin receptors noted in this disorder. Deficient cardiac sympathetic innervation is also consistent with increased vulnerability to hypoxia during delivery or in the agonal event in SIDS. Our results thus indicate that nicotine exposure in a primate model produces brainstem and autonomic abnormalities of the key monoamine systems that govern the response to hypoxia, indicate an important role of oxidative stress in the adverse effects, and point to potential amelioration strategies that could offset these particular effects of nicotine.
authors.affiliation: Department of Pharmacology & Cancer Biology, Duke University Medical Center, Durham, NC 27710, United States. t.slotkin@duke.edu
authors.forename: Theodore A
authors.initials: TA
authors.lastname: Slotkin
authors.forename: Frederic J
authors.initials: FJ
authors.lastname: Seidler
authors.forename: Eliot R
authors.initials: ER
authors.lastname: Spindel
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D015306:Biogenic Monoamines / Q000378:metabolism*; D001933:Brain Stem / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D047109:Fetal Development / Q000187:drug effects; D005318:Fetal Heart / Q000187:drug effects* / Q000378:metabolism; D005311:Fetal Hypoxia / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control; D006801:Humans; D007231:Infant, Newborn; D008253:Macaca mulatta; D009538:Nicotine / Q000097:blood / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced* / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control; D012701:Serotonin / Q000378:metabolism; D012907:Smoking / Q000009:adverse effects / Q000097:blood; D013398:Sudden Infant Death / Q000209:etiology / Q000517:prevention & control
chemical_list: D000975:Antioxidants; D015306:Biogenic Monoamines; D012701:Serotonin; D009538:Nicotine; D001205:Ascorbic Acid