Enhanced potassium-stimulated gamma-aminobutyric acid release by astrocytes derived from rats with early hepatogenic encephalopathy.
Bulk-isolated astrocytes from rats with early hepatogenic encephalopathy (HE) induced with thioacetamide responded to the increase of potassium in the incubation medium from 5 mM to 75 mM with a markedly enhanced release of previously taken up [14C]gamma-aminobutyric acid ([14C]GABA). The process was not affected by omission of calcium and/or addition of EGTA to the incubation medium. Only a slight stimulation of GABA release by high potassium was observed in astrocytes from control rats. In contrast, histamine and histidine were vigorously released from control astrocytes in high-potassium medium, and their release was not enhanced by HE, indicating that the observed phenomenon is specific for GABA.
D000818:Animals; D001253:Astrocytes / Q000187:drug effects*; D006501:Hepatic Encephalopathy / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D005680:gamma-Aminobutyric Acid; D011188:Potassium