Modulation of adenosine signalling in sheep adipose tissue by growth hormone
| Autor: | Rosemarie Doris, Gordon E. Thompson, Richard G. Vernon, Miles D. Houslay, Elaine Kilgour |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
medicine.medical_specialty
Adenosine Lipolysis Adipose tissue macrophages Adipose tissue White adipose tissue Biochemistry Piperazines chemistry.chemical_compound Tissue culture Ethers Cyclic 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine Adipocyte Internal medicine Okadaic Acid Phosphoprotein Phosphatases medicine Animals Cells Cultured Protein Kinase C Sheep Chemistry Isoproterenol Isoquinolines Adenosine receptor Recombinant Proteins Kinetics Endocrinology Adipose Tissue Growth Hormone Phenylisopropyladenosine Cattle Signal Transduction medicine.drug |
| Zdroj: | Europe PubMed Central |
| ISSN: | 1470-8752 0300-5127 |
| Popis: | Adenosine is a paracrine/autocrine antilipolytic agent that binds to A, receptors of adipocyte membranes, thereby activating GTP-binding proteins, G,, which inhibit adenylate cyclase activity and hence lipolysis. The mechanism whereby GH facilitates lipolysis is not fully explained, however it is possible that GH exerts its effects by modulating the acute regulation of this process by other hormones rather than having a direct effect on lipolysis itself. Initially studies focused on modulation of response of adipocytes to catecholamines, but very recent studies [ I , 21 suggest that the G,-mediated antilipolytic system is a major target of GH action. We have investigated this further by (a) treating sheep with recombinant bovine growth hormone, (Monsanto) 10 mg per day for 7 days in vivo and (b) by maintaining sheep adipose tissue explants in culture with GH (metabolic activities and other processes are particularly well maintained in sheep adipose tissue during culture [3]. For culture, adipose tissue explants were preincubated for 24h with no hormones and then GH (100ng/ml) was added for the next 24h. In both cases, response to adenosine in vitro was determined using N6-phenylisopropyladenosine (PIA) as described previously [2] (in essence lipolysis was activated with 100 nM isoprenaline and inhibited with various concentrations Treatment of sheep in vivo with GH decreased maximum inhibition of isoproterenol-stimulated lipolysis by 100 nM PIA from 68.8 f 11.4 to 27.8 f 9.2% (P |
| Databáze: | OpenAIRE |
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