Regulation of leptin release by insulin, glucocorticoids, Gi-coupled receptor agonists, and pertussis toxin in adipocytes and adipose tissue explants from obese humans in primary culture
| Autor: | John N. Fain, George S M Cowan, Alie Kanu, Suleiman W. Bahouth |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Leptin
medicine.medical_specialty Lipolysis Endocrinology Diabetes and Metabolism medicine.medical_treatment Adipose tissue Stimulation GTP-Binding Protein alpha Subunits Gi-Go Biology Pertussis toxin Dexamethasone chemistry.chemical_compound Endocrinology Culture Techniques Internal medicine Adipocyte Adipocytes Cyclic AMP medicine Humans Hypoglycemic Agents Insulin Obesity Prostaglandin E2 Receptor Glucocorticoids Cells Cultured Hypolipidemic Agents digestive oral and skin physiology Stimulation Chemical Adipose Tissue Pertussis Toxin chemistry hormones hormone substitutes and hormone antagonists medicine.drug |
| Zdroj: | Metabolism. 52:60-66 |
| ISSN: | 0026-0495 |
| Popis: | The basal release of leptin by adipocytes from massively obese human subjects incubated for 48 hours in serum-free suspension culture was comparable to that by explants of subcutaneous adipose tissue from the same obese individuals. There was no stimulation due to dexamethasone or insulin alone of leptin release by adipocytes. However, the combination of insulin and dexamethasone doubled leptin release by adipocytes. The release of leptin was also stimulated by agonists of G(i)-coupled receptors (prostaglandin E(2) [PGE(2)], brimonidine [an alpha(2) catecholamine agonist] and cyclopentyladenosine [CPA]) in the presence of dexamethasone. Leptin release by these agents was further enhanced by insulin in both adipocytes and adipose tissue. Pertussis toxin, which irreversibly inactivates G(i) heterotrimers, inhibited leptin release and abolished the stimulatory effects of G(i)-coupled receptor agonists. However, pertussis toxin did not block the stimulation of leptin release by insulin in either adipose tissue or adipocytes. These data indicate that the release of leptin by human adipocytes cultured for 48 hours in a serum-free medium is comparable to that by explants of adipose tissue except that dexamethasone stimulation of leptin release requires the presence of insulin. |
| Databáze: | OpenAIRE |
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