title: Glutamate release through connexin 43 by cultured astrocytes in a stimulated hypertonicity model.
abstract: We investigated the role of connexin 43 (Cx43) hemichannels in the release of glutamate by astrocytes after hypertonic stimulus. Mechanical, osmotic and oxidative stress, and changes in the extracellular or intracellular Ca(2+) levels induce connexin hemichannels located in the plasma membrane to open and release small ions and molecules with signaling potential such as glutamate, ATP, etc. In our past studies, we primarily found that acute hypertonic stimulus induced the release of glutamate. Since glutamate release was involved with several routes, we studied its release routes by astrocytes incubated in a hypertonic media for various periods. The glutamate release was increased after hypertonic stimulus. Glutamate release in hypertonic stimulus was inhibited by gap junction or Cx43 hemichannel blockers, but not by antagonists of purinergic receptor (P2XnR), glutamate transport inhibitors, intracellular Ca(2+) blockers, and pannexin 1(Panx1) hemichannel. The results suggest that glutamate release by the Cx43 hemichannels is likely to feature in the response of cultured astrocytes to hypertonic stimulus.
authors: Institute of Neuroscience, The Fourth Military Medical University, Xi'an 710032, China.
authors: Shan
authors: S
authors: Jiang
authors: Hua
authors: H
authors: Yuan
authors: Li
authors: L
authors: Duan
authors: Rong
authors: R
authors: Cao
authors: Bei
authors: B
authors: Gao
authors: Ying-Fei
authors: YF
authors: Xiong
authors: Zhi-Ren
authors: ZR
authors: Rao
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000831:Animals, Newborn; D001224:Aspartic Acid / Q000494:pharmacology; D001253:Astrocytes / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D018031:Connexin 43 / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D045604:Extracellular Fluid / Q000187:drug effects; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D006982:Hypertonic Solutions / Q000494:pharmacology*; D007031:Hypothalamus / Q000166:cytology; D009995:Osmosis / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D002614:Chelating Agents; D018031:Connexin 43; D004791:Enzyme Inhibitors; D005904:Glial Fibrillary Acidic Protein; D006982:Hypertonic Solutions; C120673:benzyloxyaspartate; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D001224:Aspartic Acid; D018698:Glutamic Acid; D004533:Egtazic Acid