[Changes in gamma-amino-butyric acid and N-methyl-D-aspartic acid receptor-gated currents from freshly isolated hippocampal CA1 pyramidal neurons of hepatic encephalopathy rats].
OBJECTIVE
To explore the effects of the changes of the amino acid receptor-gated ion-channel currents on the pathogenesis of hepatic encephalopathy (HE).


METHODS
Using rapid drug applicating device, we added 50 mumol/L gamma-amino-butyric acid (GABA) or 1 mmol/L N-methyl-D-aspartic acid (NM-DA) + 10 mumol/L Glycine (Gly) to the surrounding of freshly isolated rat hippocampal CA1 pyramidal neurons to induce receptor-gated ion-channel currents, which was recorded by whole-cell voltage-clamp technique.


RESULTS
The intensity of the GABAA-receptor mediated inward Cl- current of hippocampal CA1 pyramidal neurons of HE rats (413.3 +/- 436.8 pA, n = 31) was stronger than that of the controls (233.4 +/- 179.7 pA, n = 28, t = 2.1049, P < 0.05), and the appearance of the Cl- current in HE rats was more frequent than that in the controls. The intensity of the NMDA-receptor gated inward current in HE rats (408.5 +/- 317.2 pA, n = 37) was weeker than that in the controls (882.6 +/- 896.5 pA, n = 26, t = 2.5851, P < 0.05), but the difference of their channel opening frequency was not significant.


CONCLUSIONS
The changes of the amino acid receptor-gated ion-channel currents play an important role in the pathogenesis of hepatic encephalopathy.
Department of Surgery Third Hospital Beijing Medical University.
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Zhang
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Wu
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Zhou
D000200:Action Potentials; D000818:Animals; D002118:Calcium / Q000378:metabolism; D005260:Female; D006501:Hepatic Encephalopathy / Q000378:metabolism* / Q000503:physiopathology; D006624:Hippocampus / Q000378:metabolism* / Q000503:physiopathology; D015640:Ion Channel Gating; D008297:Male; D017966:Pyramidal Cells / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
D011963:Receptors, GABA-A; D016194:Receptors, N-Methyl-D-Aspartate; D002118:Calcium