title: Short-term regulation of adiponectin secretion in rat adipocytes.
abstract: Adiponectin belongs to the group of biologically active substances secreted by adipocytes and referred to as adipokines. Disturbances in its secretion and/or action are thought to be involved in the pathogenesis of some metabolic diseases. However, regulation of adiponectin secretion is poorly elucidated. In the present study, short-term regulation of adiponectin secretion in primary rat adipocytes was investigated. Isolated rat adipocytes were incubated in Krebs-Ringer buffer containing 5 mM glucose and insulin alone or in the combination with epinephrine, dibutyryl-cAMP, adenosine A(1) receptor antagonist (DPCPX), palmitate, 2-bromopalmitate or inhibitor of mitochondrial electron transport (rotenone). Adipocyte exposure for 2 h to insulin (1-100 nM) significantly increased secretion of adiponectin compared with secretion observed without insulin. Furthermore, secretion of adiponectin from adipocytes incubated with glucose and insulin was reduced by 1 and 2 microM epinephrine, but not by 0.25 and 0.5 microM epinephrine. Under similar conditions, 1 and 2 mM dibutyryl-cAMP substantially diminished secretion of adiponectin, whereas 0.5 mM dibutyryl-cAMP was ineffective. Secretion of adiponectin was found to be effectively decreased by DPCPX. Moreover, adipocyte exposure to rotenone also resulted in a substantial diminution of secretory response of adipocytes incubated for 2 h with glucose and insulin. It was also demonstrated that palmitate and 2-bromopalmitate (0.06-0.5 mM) failed to affect secretion of leptin. The obtained results indicated that in short-term regulation of adiponectin secretion, insulin and epinephrine exert the opposite effects. These effects appeared as early as after 2 h of exposure. Moreover, deprivation of energy or blockade of adenosine action substantially decreased secretion of adiponectin.
authors.affiliation: Department of Animal Physiology and Biochemistry, Poznan University of Life Sciences, Poznan, Poland. tszkudel@jay.up.poznan.pl
authors.forename: T
authors.initials: T
authors.lastname: Szkudelski
authors.forename: L
authors.initials: L
authors.lastname: Nogowski
authors.forename: K
authors.initials: K
authors.lastname: Szkudelska
mesh_terms: D058916:Adenosine A1 Receptor Antagonists / Q000494:pharmacology; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism*; D052242:Adiponectin / Q000378:metabolism*; D000818:Animals; D003994:Bucladesine / Q000378:metabolism / Q000494:pharmacology; D004837:Epinephrine / Q000378:metabolism / Q000494:pharmacology; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism; D008297:Male; D010168:Palmitates / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014970:Xanthines / Q000494:pharmacology
chemical_list: D058916:Adenosine A1 Receptor Antagonists; D052242:Adiponectin; D007328:Insulin; D010168:Palmitates; D014970:Xanthines; C022776:2-bromopalmitate; D003994:Bucladesine; C051360:1,3-dipropyl-8-cyclopentylxanthine; D004837:Epinephrine