Spatial and temporal alterations in the GABA shunt in the gerbil hippocampus following transient ischemia.
In the present study, we have identified the alteration in the expressions of GABA shunt-associated enzymes and the GABA transporter in order to determine the relationship between the neuronal damage and GABA metabolism following ischemia. At 30 min post-ischemia, the immunoreactivities of the glutamic acid decarboxylase (GAD) isoforms were markedly elevated in the CA1 region, as compared with the sham operated group. At 3-12 h post-ischemia, their immunoreactivities recovered at the sham level. These patterns were similarly observed up to 12 h following ischemia insult. However, the intensity of GAD67 was markedly increased at 24 h post-ischemic insult. The temporal changes in GABA transporter 1 (GAT-1) expressions were similar to that of GAD67, but not GAD65, expression, at least prior to 12 h after ischemic insults. GAT-1 immunoreactivity was significantly elevated in the CA1 region posterior to 12 h post-ischemia. Both succinic semialdehyde dehydrogenase (SSADH) and succinic semialdehyde reductase (SSAR) immunoreactivities were not altered in GABAergic neurons following ischemia. In contrast, in pyramidal cells, both SSADH and SSAR immunoreactivities showed chronological alterations in the CA1 region. Thus, our findings suggest that the differential alterations of GABA metabolism may be one of the important factors in neuronal damages induced by ischemia.
Kang
Tae-Cheon
TC
Department of Anatomy, College of Life Science, Hallym University, Chunchon, South Korea.
Park
Seung-Kook
SK
Hwang
In-Koo
IK
An
Sung-Jin
SJ
Choi
Soo Young
SY
Cho
Sung-Woo
SW
Won
Moo Ho
MH
D000445:Aldehyde Oxidoreductases / Q000378:metabolism*; D000818:Animals; D002545:Brain Ischemia / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D002352:Carrier Proteins / Q000378:metabolism*; D050485:GABA Plasma Membrane Transport Proteins; D005849:Gerbillinae; D005968:Glutamate Decarboxylase / Q000378:metabolism*; D006624:Hippocampus / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D006884:Hydroxybutyrate Dehydrogenase / Q000378:metabolism*; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D009474:Neurons / Q000378:metabolism; D027361:Organic Anion Transporters; D015427:Reperfusion Injury / Q000201:enzymology* / Q000473:pathology / Q000503:physiopathology; D050644:Succinate-Semialdehyde Dehydrogenase; D009435:Synaptic Transmission / Q000502:physiology; D013997:Time Factors; D015854:Up-Regulation / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D002352:Carrier Proteins; D050485:GABA Plasma Membrane Transport Proteins; D007527:Isoenzymes; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D027361:Organic Anion Transporters; D005680:gamma-Aminobutyric Acid; D006884:Hydroxybutyrate Dehydrogenase; C019416:4-hydroxybutyrate dehydrogenase; D000445:Aldehyde Oxidoreductases; D050644:Succinate-Semialdehyde Dehydrogenase; D005968:Glutamate Decarboxylase; C402565:glutamate decarboxylase 1; C401141:glutamate decarboxylase 2