Changes in the concentration of amino acids in the hippocampus of pentylenetetrazole-kindled rats.
It is not well recognized how disturbances in the local metabolism of some amino acids, especially glutamate and GABA, may lead to seizures. In the presented study, we have examined changes in the hippocampal steady state concentrations of amino acids involved in pentylenetetrazole-kindled and freely moving rats. It was found that in the kindled animals, the concentration of alanine, arginine, glutamate, aspartate and taurine was increased in the interictal period of seizures compared to the control group, whereas kindling reduced the extracellular levels of GABA. No differences between kindled and not-kindled animals in the glycine, histidine and glutamine levels were present. There also appeared an over fourfold increase of the Glu/GABA ratio, a theoretical marker of the neuronal excitation level, in the kindled animals. A multivariate classification tree analysis showed that the hippocampal concentration of taurine, together with GABA and Glu, had the relatively largest prediction accuracy in discriminating between kindled and non-kindled animals, suggesting a specific role of these amino acids in the shaping of a new equilibrium between excitatory and inhibitory processes in the hippocampus of kindled animals.
Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, 26/28 Krakowskie Przedmieście Street, 00-927 Warsaw, Poland. jszyndler@yahoo.com
Janusz
J
Szyndler
Piotr
P
Maciejak
Danuta
D
Turzyńska
Alicja
A
Sobolewska
Małgorzata
M
Lehner
Ewa
E
Taracha
Jerzy
J
Walkowiak
Anna
A
Skórzewska
Aleksandra
A
Wisłowska-Stanek
Adam
A
Hamed
Andrzej
A
Bidziński
Adam
A
Płaźnik
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D007696:Kindling, Neurologic; D008297:Male; D010433:Pentylenetetrazole; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*
D000596:Amino Acids; D010433:Pentylenetetrazole