CO062. PYRIDOXAMINE REDUCES THE MICROVASCULAR EFFECTS OF METHYLGLYOXAL-INDUCED GLYCATION IN ADIPOSE TISSUE

Português de Endocrinologia / 64 a Reunião Anual da SPEDM 85 quantification.Moreover, the activation of hormone-sensitive lipase (HSL) and perilipins was determined by immunofluorescence and western-blotting (WB).Adipose triglyceride lipase (ATGL) implication on melanocortin-mediated lipolysis was observed by small interference RNA.Fatty acid biosynthesis was addressed by WB analysis of the phosphorylated state of acetyl-CoA carboxilase (ACC).Fatty acid re-esterification was measured by quantifying the activity of phosphoenolpyruvate carboxykinase (PEPCK).The role of MC5R on all these processes was evaluated by siRNA.Results: a-MSH/MC5R role on lipid mobilization is mediated by HSL, ATGL and perilipins.Immunof luorescence microscopy of a-MSH-treated cells revealed that phosphorylated HSL clearly surrounds lipid droplets, in opposition to perilipins that leave the immediate periphery of lipids.These observations are lost in adipocytes with suppressed expression of MC5R.Moreover, a-MSH/MC5R decreases "de novo" synthesis of fatty acids through inactivation of ACC.Furthermore, fatty acid re-esterification is also impaired after a-MSH stimulation since a reduction on PEPCK activity was observed.Conclusion: Altogether these results indicate that, in adipocytes, a-MSH-activated MC5R regulates three tightly coupled pathways: lipolysis, lipid synthesis and re-esterification.The global effect is a decrease on adipocyte fat mass, important in strategies contributing to ameliorate obesity.This work was funded by SPEDM/ABBOTT and TANITA.Adriana R.