Effect of sex hormones on secretions of leptin and adiponectin by adipocytes

Objective To investigate the effects of sex hormones( 17 β-estradiol and testosterone)on human omental preadipocytes proliferation and differentiation and on leptin and adiponectin secretions in adipocytes.Methods Omental preadipocytes were cultured and then differentiated into mature adipocytes in vitro.The proliferation and differentiation processes of preadipocyte were observed.The preadipocytes were incubated in the presence of sex hormones and were detected the contents and gene expressions of leptin and adiponectin.Results Human preadipocytes were primarily cultured successfully.Estradiol stimulated preadipocytes proliferation (0.823±0.059 vs 0.276 ±0.032,P＜0.05 ),and inhibited lipid accumulation in cell differentiation ( P＜0.05 ).Testosterone had no significant effect on proliferation of preedipocytes,but inhibited adipogenic differentiation ( P＜0.05).Leptin could be detected during proliferation and differentiation of preadipocytes.Estradiol increased the leptin secretion,whereas testosterone reduced it ( all P ＜ 0.05 ).The adiponectin only could be detected during differentiation.Sex hormones reduced the adiponectin secretion.17β-estradiol stimulated leptin mRNA expression and suppressed adiponectin mRNA expression in adipocytes.Testosterone suppressed the mRNA expressions of leptin and adiponectin (all P ＜ 0.05 ).Conclusion In vitro,17β-estradiol increases the leptin secretion and mRNA expression whereas reduced the adiponectin secretion and mRNA expression.Testosterone reduced the adiponectin and leptin secretion and mRNA expression. Key words: Adipocytes;  17β-estradiol;  Testosterone;  Leptin;  Adiponectin