瘦素对脂肪细胞的直接调节作用

目的:观察瘦素对人脂肪细胞分解代谢及脂肪蓄积的直接影响,探讨脂肪细胞的自分泌调节作用。方法:取正常成人皮下脂肪组织,常规提取和培养前脂肪细胞,待细胞融合后诱导分化为成熟脂肪细胞并随机分为四组:正常对照组、低浓度组、中浓度组和高浓度组,分别培养于含瘦素浓度为0ng/ml、10ng/ml、100ng/ml、1000ng/ml的培养液a中。培养4h后收集培养液检测游离脂肪酸和甘油浓度,取脂肪细胞经油红O染色后图像分析计算脂肪颗粒的积分光密度。结果:与对照组相比,低浓度组培养液中游离脂肪酸和甘油浓度分别增加87%(P<0.01)和5%(P<0.01),脂肪颗粒积分光密度减少12%(P<0.01);中浓度组培养液中游离脂肪酸和甘油浓度分别增加181%(P<0.01)和8%(P<0.01),脂肪颗粒光密度减少21%(P<0.01);高浓度组培养液中游离脂肪酸和甘油的浓度分别增加312%(P<0.01)和17%(P<0.01),脂肪颗粒的积分光密度减少35%(P<0.01)。游离脂肪酸和甘油浓度与瘦素浓度呈正相关,脂肪颗粒积分光密度与瘦素浓度呈负相关。结论:瘦素瞬时作用脂肪细胞,可促进脂肪分解代谢、减少脂肪蓄积;且随着瘦素浓度增加,作用更强,呈剂量依赖性。瘦素对脂肪细胞存在自分泌调节作用,可能在肥胖发病机制中起重要作用。

The direct effect of leptin on adipocyte

Objective To investigate the direct effect of leptin on lipolysis and lipopexia of human adipocyte,and to explore the autocrine regulation of adipocyte.Methods Subcutaneous fatty tissue of adult normal were prepared,then preadipocyte were cultured and induced to differentiate.After identified by oil red staining,adipocyte were divided randomly into four groups,i.e.normal control group,low concentration group,media concentration group and high concentration group,in which the concentration of lepin were 0ng/ml,10ng/ml,100ng/ml,1000ng/ml respectively.Media from the four groups were collected after cultured 4h to detect the concentration of free fatty acid and glycerol,and meanwhile the cells were stained by oil red and evaluated the content of lipochondria.Results Compared with normal control group,the concentration of free fatty acid and glycerol were increased 87%,5%(P<0.01)respectively in low.concentration group,and up-regulated 312%(P<0.01),17%(P<0.01)respectively in high concentration group.Meanwhile,the integral optical density(IOD)of lipochondria was decreased 12%(P<0.01)in low.concentration group,and down-regulated 35%(P<0.01)in high concentration group.In addition,the concentration of free fatty acid and glycerol were positive correlated with the dose of letin,but the IOD of lipochondria negative correlated with it.Conclusion There is transient action of lepin on adipocyte,which is positive correlation with the concentration of leptin and was found to promote the lipolysis of adipocyte and reduce the accumulation of fat.The autocrine regulation of adipocyte may be important for obesity.