In situ transblot and immunocytochemical comparisons of astrocytic connexin-43 responses to NMDA and kainic acid in rat brain.
Intracerebral injection of kainic acid (KA) in rat brain was previously found to cause altered immunohistochemical recognition of connexin-43 (Cx43) epitopes (epitope masking) with different sequence-specific antibodies against this gap junction protein. We demonstrate here that similar alterations occur when nitrocellulose membranes containing protein transferred from fresh cryostat sections of KA-injected brain are probed with these antibodies (in situ transblotting), indicating that epitope masking is not a result of epitope alteration due to fixation conditions used in earlier studies. Alterations in immuno-recognition of astrocytic Cx43 subsequent to injections of NMDA were also observed and were similar to those seen with KA in some, but not all respects. The results provide further indications of Cx43 molecular modification in excitotoxin-lesioned tissue and suggest that the sequelae of reactions by astrocytes and their gap junctions in these tissues is dependent on cell-type susceptibility to excitotoxin action.
Sawchuk
M A
MA
Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
Hossain
M Z
MZ
Hertzberg
E L
EL
Nagy
J I
JI
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D018031:Connexin 43 / Q000378:metabolism*; D000939:Epitopes / Q000276:immunology; D017629:Gap Junctions / Q000187:drug effects; D015151:Immunoblotting; D007150:Immunohistochemistry; D007608:Kainic Acid / Q000494:pharmacology*; D008297:Male; D008567:Membranes, Artificial; D016202:N-Methylaspartate / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D018031:Connexin 43; D000939:Epitopes; D008567:Membranes, Artificial; D016202:N-Methylaspartate; D007608:Kainic Acid