CRISTIAN SCHEAU, IOANA ANCA BADARAU, IOANA GABRIELA LUPESCU, IOANA RALUCA PAPACOCEA, GRATIELA LIVIA MIHAI, MARIUS TOMA PAPACOCEA, ANDREEA ELENA SCHEAU THE PIVOTAL ROLE OF THE GLUTAMATE - GLUTAMINE CYCLE IN MINIMAL HEPATIC ENCEPHALOPATHY AN EXPERIMENTAL MAGNETIC RESONANCE SPECTROSCOPY STUDY
The glutamate-glutamine cycle is essential for sustaining the neuronal secretion of the excitatory neurotransmitter glutamate. Hepatic encephalopathy, even in its most discreet form, minimal hepatic encephalopathy (MHE), interferes with the glutamate and glutamine balance due to the increase in ammonia levels in the central nervous system (CNS), induced by a combination of liver dysfunction, increased blood-brain barrier permeability and many other factors. An experimental study on 21 patients with chronic liver disease and 11 healthy volunteers was performed. Magnetic resonance spectroscopy demonstrated an increase of the glutamate-glutamine complex peak, with high predictive value for MHE, especially when the metabolites are referenced to creatine, a stabile metabolite in the CNS. This paper also explores the pathophysiology of MHE with emphasis on the involvement of the glutamate-glutamine cycle in the development of this complication.
Keywords: glutamate, glutamine, creatine, minimal hepatic encephalopathy, magnetic resonance spectroscopy