Serotonin (5-HT) and 5-HT2A receptor agonists suppress lipolysis in primary rat adipose cells.
Serotonin (5-HT) is a biogenic monoamine that functions both as a neurotransmitter and a circulating hormone. Recently, the metabolic effects of 5-HT have gained interest and peripheral 5-HT has been proposed to influence lipid metabolism in various ways. Here, we investigated the metabolic effects of 5-HT in isolated, primary rat adipose cells. Incubation with 5-HT suppressed β-adrenergically stimulated glycerol release and decreased phosphorylation of protein kinase A (PKA)-dependent substrates, hormone sensitive lipase (Ser563) and perilipin (Ser522). The inhibitory effect of 5-HT on lipolysis enhanced the anti-lipolytic effect of insulin, but sustained in the presence of phosphodiesterase inhibitors, OPC3911 and isobuthylmethylxanthine (IBMX). The relative expression of 5-HT1A, -2B and -4 receptor class family were significantly higher in adipose tissue compared to adipose cells, whereas 5-HT1D, -2A and -7 were highly expressed in isolated adipose cells. Similar to 5-HT, 5-HT2 receptor agonists reduced lipolysis while 5-HT1 receptor agonists rather decreased non-stimulated and insulin-stimulated glucose uptake. Together, these data provide evidence of a direct effect of 5-HT on adipose cells, where 5-HT suppresses lipolysis and glucose uptake, which could contribute to altered systemic lipid- and glucose metabolism.
Glucose Transport and Protein Trafficking, Department of Experimental Medical Science, Lund University Diabetes Centre, Biomedical Centre, Lund University, 221 84 Lund, Sweden.
Björn
B
Hansson
Unit of Molecular Metabolism, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, 20502 Malmö, Sweden.
Anya
A
Medina
Glucose Transport and Protein Trafficking, Department of Experimental Medical Science, Lund University Diabetes Centre, Biomedical Centre, Lund University, 221 84 Lund, Sweden.
Claes
C
Fryklund
Unit of Molecular Metabolism, Department of Clinical Sciences, Lund University Diabetes Centre, Clinical Research Centre, 20502 Malmö, Sweden.
Malin
M
Fex
Glucose Transport and Protein Trafficking, Department of Experimental Medical Science, Lund University Diabetes Centre, Biomedical Centre, Lund University, 221 84 Lund, Sweden. Electronic address: karin.stenkula@med.lu.se.
Karin G
KG
Stenkula
D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D008066:Lipolysis / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*; D017366:Serotonin Receptor Agonists / Q000008:administration & dosage*
D044402:Receptor, Serotonin, 5-HT2A; D017366:Serotonin Receptor Agonists; D012701:Serotonin
5-HT; Adipose cells; Lipid metabolism; Lipolysis; Serotonin