Role of Hydrogen Sulfide and Polysulfides in the Regulation of Lipolysis in the Adipose Tissue: Possible Implications for the Pathogenesis of Metabolic Syndrome.

Hydrogen sulfide (HS) and inorganic polysulfides are important signaling molecules; however, little is known about their role in the adipose tissue. We examined the effect of HS and polysulfides on adipose tissue lipolysis. HS and polysulfide production by mesenteric adipose tissue explants in rats was measured. The effect of NaS and NaS, the HS and polysulfide donors, respectively, on lipolysis markers, plasma non-esterified fatty acids (NEFA) and glycerol, was examined. NaS but not NaS increased plasma NEFA and glycerol in a time- and dose-dependent manner. NaS increased cyclic AMP but not cyclic GMP concentration in the adipose tissue. The effect of NaS on NEFA and glycerol was abolished by the specific inhibitor of protein kinase A, KT5720. The effect of NaS on lipolysis was not abolished by propranolol, suggesting no involvement of β-adrenergic receptors. In addition, NaS had no effect on phosphodiesterase activity in the adipose tissue. Obesity induced by feeding rats a highly palatable diet for 1 month was associated with increased plasma NEFA and glycerol concentrations, as well as greater HS production in the adipose tissue. In conclusion, HS stimulates lipolysis and may contribute to the enhanced lipolysis associated with obesity.