| Autor: |
Heffernan M; Department of Biochemistry and Molecular Biology, Monash University, Clayton, Australia 3800., Summers RJ, Thorburn A, Ogru E, Gianello R, Jiang WJ, Ng FM |
| Jazyk: |
angličtina |
| Zdroj: |
Endocrinology [Endocrinology] 2001 Dec; Vol. 142 (12), pp. 5182-9. |
| DOI: |
10.1210/endo.142.12.8522 |
| Abstrakt: |
Both human GH (hGH) and a lipolytic fragment (AOD9604) synthesized from its C-terminus are capable of inducing weight loss and increasing lipolytic sensitivity following long-term treatment in mice. One mechanism by which this may occur is through an interaction with the beta-adrenergic pathway, particularly with the beta(3)-adrenergic receptors (beta(3)-AR). Here we describe how hGH and AOD9604 can reduce body weight and body fat in obese mice following 14 d of chronic ip administration. These results correlate with increases in the level of expression of beta(3)-AR RNA, the major lipolytic receptor found in fat cells. Importantly, both hGH and AOD9604 are capable of increasing the repressed levels of beta(3)-AR RNA in obese mice to levels comparable with those in lean mice. The importance of beta(3)-AR was verified when long-term treatment with hGH and AOD9604 in beta(3)-AR knock-out mice failed to produce the change in body weight and increase in lipolysis that was observed in wild-type control mice. However, in an acute experiment, AOD9604 was capable of increasing energy expenditure and fat oxidation in the beta(3)-AR knock-out mice. In conclusion, this study demonstrates that the lipolytic actions of both hGH and AOD9604 are not mediated directly through the beta(3)-AR although both compounds increase beta(3)-AR expression, which may subsequently contribute to enhanced lipolytic sensitivity. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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