Objective:To explore the effects of tumor necrosis factor-α(TNF-α) on retinol binding protein 4 (RBP4) secreted by mature 3T3-L1 adipocytes in-vitro.Methods:3T3-L1 preadipocytes were cultured and differentiated into the mature adipocytes after 2 days of confluenence.Recombinant TNF-αat different concentrations was added to the culture medium of fully differentiated adipocytes.Total protein of RBP4 secreted by these adipocytes was evaluated by radioimmunoassay(RIA) at various times.Results:(1)Treatment of mature 3T3-L1 adipocytes with TNF-αat different concentrations (0.2

1.0

5.0

10ng/ml) decreased RBP4 secretion.The inhibitive effect of TNF-αon RBP4 was in dose dependent manner.The level of RBP4 decreased along with the elevated TNF-αconcentration in the culture medium.(2)Almost the RBP4 secretion in all experiment groups had a decreasing tread at different time points

but there was no statistical difference in each group.(3) Regression analysis indicated TNF-αhad significant associations with RBP4.Conclusion:TNF-αinhibits mature adipocytes RBP4 secretion in-vitro in dose-response effects

but there is no time-response effects.