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Biological effects of human growth hormone in rat adipocyte precursor cells and newly differentiated adipocytes in primary culture.
- Source :
-
Metabolism: clinical and experimental [Metabolism] 1996 Jan; Vol. 45 (1), pp. 34-42. - Publication Year :
- 1996
-
Abstract
- The effects of human growth hormone (hGH) on proliferation and differentiation of primary adipocyte precursor cells isolated from rat epididymal fat pads were studied under serum-free culture conditions. hGH markedly reduced the formation of new fat cells and the expression of glycerophosphate dehydrogenase activity, a marker enzyme of adipose differentiation, in a dose-dependent manner. To find an explanation for this inhibitory effect, we investigated the action of GH on (1) cell proliferation and on (2) lipid accumulation, the latter in the absence and presence of corticosterone. In undifferentiated cells, 5 nmol/L hGH increased both cell number and [3H]-thymidine incorporation (1.3- and 2.6-fold over basal, respectively). This effect was mediated by insulin-like growth factor-I (IGF-I), since hGH stimulated IGF-I production in undifferentiated cells by 12-fold and addition of an anti-IGF-I monoclonal antibody (IGF-I MAb) abolished the mitogenic effect of hGH but did not prevent hGH-induced suppression of adipose differentiation. In developing fat cells, hGH significantly reduced cellular 2-deoxyglucose uptake and glucose incorporation into lipids. In addition, hGH exhibited a lipolytic action in the presence of insulin and triiodothyronine. These effects were not prevented by IGF-I MAb. Specific binding of [125I]-hGH to precursor cells increased significantly during adipose conversion. In differentiated cells Scatchard analysis yielded linear plots with an apparent Kd of 0.16 nmol/L and 8,400 sites per cell. Taken together, these data show that hGH reduces adipose conversion in primary cultures of rat adipocyte precursor cells while promoting cell proliferation through an increase in IGF-I production.
- Subjects :
- Adipocytes cytology
Adipocytes enzymology
Animals
Antibodies, Monoclonal immunology
Antibodies, Monoclonal pharmacology
Cell Differentiation drug effects
Cell Differentiation physiology
Cell Division drug effects
Cell Division physiology
Cells, Cultured
Corticosterone pharmacology
Dose-Response Relationship, Drug
Glucose pharmacokinetics
Glycerolphosphate Dehydrogenase analysis
Humans
Insulin-Like Growth Factor I immunology
Iodine Radioisotopes
Lipid Metabolism
Lipolysis physiology
Male
Rats
Rats, Wistar
Stem Cells cytology
Stem Cells enzymology
Thymidine metabolism
Tritium
Adipocytes drug effects
Growth Hormone pharmacology
Stem Cells drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 0026-0495
- Volume :
- 45
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Metabolism: clinical and experimental
- Publication Type :
- Academic Journal
- Accession number :
- 8544774
- Full Text :
- https://doi.org/10.1016/s0026-0495(96)90197-3