Metabolic inhibition induces opening of unapposed connexin 43 gap junction hemichannels and reduces gap junctional communication in cortical astrocytes in culture.

ABSTRACT: Rat cortical astrocytes in pure culture are functionally coupled to neighboring cells via connexin (Cx) 43 gap junctions under ordinary conditions. Small fluorescent molecules such as Lucifer yellow (LY) pass between cell interiors via gap junctions, but do not enter the cells when externally applied. Subjecting rat and mouse cortical astrocytes to "chemical ischemia" by inhibition of glycolytic and oxidative metabolism induced permeabilization of cells to Lucifer yellow and ethidium bromide before loss of membrane integrity determined by dextran uptake and lactate dehydrogenase release. The gap junction blockers octanol and 18alpha-glycyrrhetinic acid markedly reduced dye uptake, suggesting that uptake was mediated by opening of unapposed hemichannels. Extracellular La(3+) also reduced dy

SUBMITTER: Contreras JE 

PROVIDER: S-EPMC117588 | biostudies-literature | 2002 Jan

REPOSITORIES: biostudies-literature