title: Apoptosis dependent decrease of the intramembrane ion traffic in cultured mouse fibroblasts shown by conductivity dispersion.
abstract: We have investigated the intramembranal ion traffic in apoptotic 3T6 cells in culture. Apoptosis was induced by various treatments, such as serum deprivation, high density growth and hydrogen peroxide at subnecrotic doses. Cell death was assessed by nucleosomal DNA fragmentation, single cell electrophoresis, immunofluorescence and histological staining. To study the modifications of membrane structure and function, we adopted a well established biophysical strategy based on the measurement of the electrical conductivity of cell suspensions, as a function of the frequency of the electrical field applied to the sample. A comparison between the conductivity of normal and apoptotic cell suspensions shows that programmed cell death causes a decrease of membrane conductivity which indicates a diminished intramembranal ion traffic. Our results strongly suggest that one of the early events in the triggering of apoptosis is represented by an overall reduction of plasma membrane function. Finally, our results are in agreement with the idea that the nucleus is not the sole target of the apoptotic process.
authors.affiliation: Dipartimento di Genetica e Biologia Molecolare, Università di Roma La Sapienza.
authors.forename: A
authors.initials: A
authors.lastname: Bonincontro
authors.forename: A
authors.initials: A
authors.lastname: Iacoangeli
authors.forename: G
authors.initials: G
authors.lastname: Melucci-Vigo
authors.forename: G
authors.initials: G
authors.lastname: Risuleo
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D002462:Cell Membrane / Q000737:chemistry / Q000502:physiology*; D002839:Chromans / Q000494:pharmacology; D016895:Culture Media, Serum-Free; D004553:Electric Conductivity; D005347:Fibroblasts; D006861:Hydrogen Peroxide / Q000494:pharmacology; D017136:Ion Transport; D051379:Mice; D013329:Structure-Activity Relationship
chemical_list: D000975:Antioxidants; D002839:Chromans; D016895:Culture Media, Serum-Free; D006861:Hydrogen Peroxide; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid