title: Modeling the developmental neurotoxicity of nicotine in vitro: cell acquisition, growth and viability in PC12 cells.
abstract: Although nicotine is a developmental neurotoxicant, it also can exert neuroprotective effects. In the current study, we used PC12 cells to determine the developmental phases in which these disparate actions are expressed and to compare the concentrations required for each. In undifferentiated cells, 1 or 10 microM nicotine had little or no effect on cell number (assessed by measuring DNA) but exerted positive trophic actions, characterized by transient enhancement of cell growth (increased total protein/DNA ratio) and persistent enhancement of cell viability (decreased proportions of cells stained with trypan blue). When differentiation was initiated with nerve growth factor, nicotine elicited a different spectrum of actions, with decreases in cell number, impaired neuritic outgrowth (reduced ratio of membrane/total protein) and weakened viability. In either undifferentiated or differentiating cells, nicotine increased lipid peroxidation (determined as thiobarbituric acid reactive species), providing evidence for oxidative damage. Our results indicate that nicotine exerts positive trophic effects primarily on undifferentiated cells, whereas with differentiation the effects undergo a transition to neurotoxicity. These findings support the view that the neurodevelopmental actions of nicotine depend not only upon the magnitude and duration of the exposure, but most importantly on the developmental stage (e.g., differentiation state) in which exposure occurs.
authors.affiliation: Department of Pharmacology and Cancer Biology, Duke University Medical Center, Box 3813 DUMC, Durham, NC 27710, USA.
authors.forename: Yael
authors.initials: Y
authors.lastname: Abreu-Villaça
authors.forename: Frederic J
authors.initials: FJ
authors.lastname: Seidler
authors.forename: Dan
authors.initials: D
authors.lastname: Qiao
authors.forename: Theodore A
authors.initials: TA
authors.lastname: Slotkin
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002452:Cell Count / Q000379:methods; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D020932:Nerve Growth Factor / Q000494:pharmacology; D009498:Neurotoxins / Q000633:toxicity*; D009538:Nicotine / Q000633:toxicity*; D016716:PC12 Cells; D051381:Rats; D013194:Staining and Labeling / Q000379:methods; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D009498:Neurotoxins; D017392:Thiobarbituric Acid Reactive Substances; D009538:Nicotine; D004247:DNA; D020932:Nerve Growth Factor