Adenylyl cyclase activity and glucose release from the liver of the European eel,Anguilla anguilla
| Autor: | Antonio Capuzzo, Carla Biondi, Elena Fabbri, Laura Barbin |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
medicine.medical_specialty
Epinephrine Adrenergic receptor Physiology Guanosine chemistry.chemical_element Biology Calcium Adenylyl cyclase chemistry.chemical_compound Phentolamine Physiology (medical) Internal medicine medicine Animals Adrenergic receptors Forskolin Anguilla Adrenergic Agonists Receptors Adrenergic Glucose medicine.anatomical_structure Endocrinology Liver chemistry Hepatocyte Ionomycin Adenylyl Cyclases medicine.drug |
| Zdroj: | Europe PubMed Central Scopus-Elsevier |
| ISSN: | 1522-1490 0363-6119 |
| DOI: | 10.1152/ajpregu.1998.275.5.r1563 |
| Popis: | The properties of adenylyl cyclase (AC) in liver membranes of the European eel ( Anguilla anguilla) and the involvement of cAMP in glucose release from isolated hepatocytes in response to catecholamines were studied. Basal enzyme activity seemed essentially unaffected by GTP, while a biphasic response to increasing nucleotide concentrations was obtained in the presence of epinephrine. Eel liver AC was dose-dependently stimulated by guanosine 5′- O-(3-thiotriphosphate) and inhibited by guanosine 5′- O-(2-thiodiphosphate). AC activity, intracellular cAMP levels, and glucose release from isolated hepatocytes were significantly enhanced by NaF, forskolin, epinephrine, and phenylephrine. The rise in cAMP production stimulated by catecholamines was counteracted by propranolol, but not by phentolamine. Catecholamine-induced glucose output was instead partially antagonized by both phentolamine and propranolol. Complete inhibition was obtained only by the simultaneous presence of the two adrenergic antagonists. Glucose release from the cells was induced by dibutyryl cAMP and by the calcium ionophore ionomycin. In summary, these data provide the first characterization of eel liver AC system and suggest a direct role for cAMP in the catecholamine-dependent glucose output. Furthermore, the involvement of calcium ions in this cellular response is hypothesized. |
| Databáze: | OpenAIRE |
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