Decreased hepatic response to glucagon, adrenergic agonists, and cAMP in glycogenolysis, gluconeogenesis, and glycolysis in tumor-bearing rats
| Autor: | Isabele G. Frasson, Giuliana Regina Biazi, Flaviane de Fatima Silva, Gisele Lopes Bertolini, Helenir Medri de Souza, Daniele Romani Miksza, Hely de Morais |
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| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Male medicine.medical_specialty Glycogenolysis Cachexia Adrenergic Carbohydrate metabolism Biochemistry Glucagon 03 medical and health sciences chemistry.chemical_compound Phenylephrine 0302 clinical medicine Adenosine Triphosphate Internal medicine Neoplasms medicine Cyclic AMP Animals Cyclic adenosine monophosphate Glycolysis Rats Wistar Molecular Biology Gluconeogenesis Isoproterenol Cell Biology Adrenergic beta-Agonists Adrenergic Agonists Rats Perfusion 030104 developmental biology Endocrinology chemistry Liver 030220 oncology & carcinogenesis Adrenergic alpha-1 Receptor Agonists medicine.drug |
| Zdroj: | Journal of cellular biochemistry. 119(9) |
| ISSN: | 1097-4644 |
| Popis: | The response to glucagon and adrenaline in cancer cachexia is poorly known. The aim of this study was to investigate the response to glucagon, adrenergic agonists (α and β) and cyclic adenosine monophosphate (cAMP) on glycogenolysis, gluconeogenesis, and glycolysis in liver perfusion of Walker-256 tumor-bearing rats with advanced cachexia. Liver ATP content was also investigated. Rats without tumor (healthy) were used as controls. Agonists α (phenylephrine) and β (isoproterenol) adrenergic, instead of adrenaline, and cAMP, the second messenger of glucagon and isoproterenol, were used in an attempt to identify mechanisms involved in the responses. Glucagon (1 nM) stimulated glycogenolysis and gluconeogenesis and inhibited glycolysis in the liver of healthy and tumor-bearing rats, but their effects were lower in tumor-bearing rats. Isoproterenol (20 µM) stimulated glycogenolysis, gluconeogenesis, and glycolysis in healthy rats and had virtually no effect in tumor-bearing rats. cAMP (9 µM) also stimulated glycogenolysis and gluconeogenesis and inhibited glycolysis in healthy rats but had practically no effect in tumor-bearing rats. Phenylephrine (2 µM) stimulated glycogenolysis and gluconeogenesis and inhibited glycolysis and these effects were also lower in tumor-bearing rats than in healthy. Liver ATP content was lower in tumor-bearing rats. In conclusion, tumor-bearing rats with advanced cachexia showed a decreased hepatic response to glucagon, adrenergic agonists (α and β), and cAMP in glycogenolysis, gluconeogenesis, and glycolysis, which may be due to a reduced rate of regulatory enzyme phosphorylation caused by the low ATP levels in the liver. |
| Databáze: | OpenAIRE |
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