| First Author | Erraji-Benchekroun L | Year | 2005 |
| Journal | Am J Physiol Endocrinol Metab | Volume | 288 |
| Issue | 4 | Pages | E715-22 |
| PubMed ID | 15585594 | Mgi Jnum | J:97235 |
| Mgi Id | MGI:3575031 | Doi | 10.1152/ajpendo.00113.2004 |
| Citation | Erraji-Benchekroun L, et al. (2005) Overexpression of beta2-adrenergic receptors in mouse liver alters the expression of gluconeogenic and glycolytic enzymes. Am J Physiol Endocrinol Metab 288(4):E715-22 |
| abstractText | In the livers of humans and many other mammalian species, beta2-adrenergic receptors (beta2-ARs) play an important role in the modulation of glucose production by glycogenolysis and gluconeogenesis. In male mice and rats, however, the expression and physiological role of hepatic beta2-ARs are rapidly lost with development under normal physiological conditions. We previously described a line of transgenic mice, F28 (Andre C, Erraji L, Gaston J, Grimber G, Briand P, and Guillet JG. Eur J Biochem 241: 417-424, 1996), which carry the human beta2-AR gene under the control of its own promoter. In these mice, hepatic beta2-AR levels are shown to increase rapidly after birth and, as in humans, be maintained at an elevated level in adulthood. F28 mice display strongly enhanced adenylyl cyclase responses to beta-AR agonists in their livers and, compared with normal mice, have increased basal hepatic adenylyl cyclase activity. In this report we demonstrate that, under normal physiological conditions, this increased beta2-AR activity affects the expression of the gluconeogenic and glycolytic key enzymes phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and l-pyruvate kinase and considerably decreases hepatic glycogen levels. Furthermore, we show that the effects of beta-adrenergic ligands on liver glycogen observed in humans are reproduced in these mice: liver glycogen levels are strongly decreased by the beta2-AR agonist clenbuterol and increased by the beta-AR antagonist propranolol. These transgenic mice open new perspectives for studying in vivo the hepatic beta2-AR system physiopathology and for testing the effects of beta-AR ligands on liver metabolism. |
