BACKGROUND: Glutamine synthetase (GS) plays a central role in the inter-organ metabolism of ammonia and hepatic encephalopathy. The main objective of the present work was to disclose the possible effect of exercise on GS mRNA expression in peripheral blood mononuclear cells (PBMC) within a group of healthy volunteers. MATERIAL AND METHODS: PBMC were studied instead of skeletal muscle because of ethical concerns. Characterization of GS in lymphocytes was carried out by indirect immunofluorescence and Western blot. After a pilot trial, expression of GS mRNA in PBMC was assayed by serial measurements in healthy volunteers who had exercised on a treadmill, and on a control group who had not. Muscle mass was estimated by bioimpedance. RESULTS: Cytoplasmic GS had a molecular weight of 44 kDa. Serial measurements of its mRNA demonstrated an increase in the treadmill (n = 29), but not in the control group (n = 13) (p < 0.05). Peak expression occurred at 1 h in males and at 6 h in females. There was a positive correlation between muscle mass and the increase of the enzyme mRNA after exercise. CONCLUSION: Exercise can increase the expression of GS mRNA in PBMC in healthy volunteers. Based on these preliminary results and on well-established physiological concepts, a hypothesis for non-hepatic ammonia metabolism is conceived. In the future could become part of the treatment of low-grade hepatic encephalopathy.
BACKGROUND:Glutamine synthetase (GS) plays a central role in the inter-organ metabolism of ammonia and hepatic encephalopathy. The main objective of the present work was to disclose the possible effect of exercise on GS mRNA expression in peripheral blood mononuclear cells (PBMC) within a group of healthy volunteers. MATERIAL AND METHODS: PBMC were studied instead of skeletal muscle because of ethical concerns. Characterization of GS in lymphocytes was carried out by indirect immunofluorescence and Western blot. After a pilot trial, expression of GS mRNA in PBMC was assayed by serial measurements in healthy volunteers who had exercised on a treadmill, and on a control group who had not. Muscle mass was estimated by bioimpedance. RESULTS: Cytoplasmic GS had a molecular weight of 44 kDa. Serial measurements of its mRNA demonstrated an increase in the treadmill (n = 29), but not in the control group (n = 13) (p < 0.05). Peak expression occurred at 1 h in males and at 6 h in females. There was a positive correlation between muscle mass and the increase of the enzyme mRNA after exercise. CONCLUSION: Exercise can increase the expression of GS mRNA in PBMC in healthy volunteers. Based on these preliminary results and on well-established physiological concepts, a hypothesis for non-hepatic ammonia metabolism is conceived. In the future could become part of the treatment of low-grade hepatic encephalopathy.
Authors: Eva Román; Maria Teresa Torrades; Maria Josep Nadal; Guillem Cárdenas; Juan Camilo Nieto; Sílvia Vidal; Helena Bascuñana; Cándido Juárez; Carlos Guarner; Juan Córdoba; Germán Soriano Journal: Dig Dis Sci Date: 2014-03-06 Impact factor: 3.199
Authors: Astrid Ruiz-Margáin; Ricardo Ulises Macías-Rodríguez; Javier Ampuero; Francisco Javier Cubero; Luis Chi-Cervera; Silvia L Ríos-Torres; Andrés Duarte-Rojo; Ángeles Espinosa-Cuevas; Manuel Romero-Gómez; Aldo Torre Journal: World J Gastroenterol Date: 2016-12-07 Impact factor: 5.742