title: Ouabain modulates cell contacts as well as functions that depend on cell adhesion.
abstract: Ouabain, a toxic of vegetal origin used for centuries to treat heart failure, has recently been demonstrated to have an endogenous counterpart, most probably ouabain itself, which behaves as a hormone. Therefore, the challenge now is to discover the physiological role of hormone ouabain. We have recently shown that it modulates cell contacts such as gap junctions, which communicate neighboring cells, as well as tight junctions (TJs), which are one of the two differentiated features of epithelial cells, the other being apical/basolateral polarity. The importance of cell contacts can be hardly overestimated, since the most complex object in the universe, the brain, assembles itself depending on what cells contacts what other(s) how, when, and how is the molecular composition and special arrangement of the contacts involved. In the present chapter, we detail the protocols used to demonstrate the effect of ouabain on the molecular structure and functional properties of one of those cell-cell contacts: the TJ.
authors.affiliation: Center for Research & Advanced Studies (CINVESTAV), Mexico City, México.
authors.forename: Isabel
authors.initials: I
authors.lastname: Larre
authors.forename: Ruben G
authors.initials: RG
authors.lastname: Contreras
authors.forename: Marcelino
authors.initials: M
authors.lastname: Cereijido
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002448:Cell Adhesion / Q000187:drug effects; D002450:Cell Communication / Q000187:drug effects* / Q000502:physiology*; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D062445:Claudin-1; D017630:Connexins / Q000235:genetics / Q000378:metabolism; D003911:Dextrans / Q000032:analysis; D004285:Dogs; D017097:Electric Impedance; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000032:analysis; D017629:Gap Junctions / Q000187:drug effects / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology*; D010957:Plasmids; D011199:Potentiometry / Q000379:methods*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism*; D014162:Transfection
chemical_list: D062445:Claudin-1; D017630:Connexins; D003911:Dextrans; D008565:Membrane Proteins; D012333:RNA, Messenger; C015219:fluorescein isothiocyanate dextran; D010042:Ouabain; D016650:Fluorescein-5-isothiocyanate