Kainic acid seizures in the rat: differential expression of chromogranin A, carboxypeptidase H and peptidylglycine alpha-amidating monooxigenase in subfields of the hippocampal formation.
Using in situ hybridization histochemistry concentrations of mRNAs encoding chromogranin A (ChA), carboxypeptidase H (CPH) and peptidylglycine alpha-amidating monooxigenase (PAM) have been investigated in the hippocampus after kainic acid (KA)-induced limbic seizures in the rat. Increased concentrations (by 150%) of ChA and CPH mRNAs were found in the granule cell layer 24 h after KA injection. At the same time PAM mRNA levels were only slightly elevated (by 50%). Whereas the increases in CPH and PAM transcripts were only transient, ChA mRNA concentrations in the granule cell layer were elevated up to 2 months after the initial seizures. In contrast, in the pyramidal cell layers of all hippocampal subfields (CA1 to CA3) ChA mRNA concentrations were significantly reduced (by 40-70%) 1-60 days after KA. PAM and CPH messages were slightly reduced in the pyramidal cell layer of CA1 but not in CA2 and CA3. The experiments demonstrate that KA-induced limbic seizures cause sustained changes in the expression of ChA mRNA. At the same time the expression of two enzymes involved in post-translational processing of neuropeptides, PAM and CPH, becomes only transiently altered. Synthesis of ChA may be regulated differently in the strata granulosum and pyramidale during epileptic seizures.
Mahata
S K
SK
Department of Pharmacology, University of Innsbruck, Austria.
Gruber
B
B
Mahata
M
M
Röder
C
C
Fischer-Colbrie
R
R
Sperk
G
G
D000818:Animals; D001345:Autoradiography; D043423:Carboxypeptidase H; D002268:Carboxypeptidases / Q000096:biosynthesis*; D053379:Chromogranin A; D002864:Chromogranins / Q000096:biosynthesis*; D015870:Gene Expression / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D017403:In Situ Hybridization; D007608:Kainic Acid / Q000633:toxicity*; D008297:Male; D006899:Mixed Function Oxygenases / Q000096:biosynthesis*; D009097:Multienzyme Complexes; D009498:Neurotoxins / Q000633:toxicity*; D017966:Pyramidal Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis* / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D013462:Sulfur Radioisotopes
D053379:Chromogranin A; D002864:Chromogranins; D009097:Multienzyme Complexes; D009498:Neurotoxins; D012333:RNA, Messenger; D013462:Sulfur Radioisotopes; C506153:chromogranin A, rat; D006899:Mixed Function Oxygenases; C035189:peptidylglycine monooxygenase; D002268:Carboxypeptidases; D043423:Carboxypeptidase H; D007608:Kainic Acid