[Effects of dibutyl phthalate and monobutyl phthalate on testosterone secretion and insulin-like factor 3 expression of Leydig tumor cells in mice].

Objective To observe the effects ofdibutyl phthalate (DBP) and monobutyl phthalate (MBP) on the mRNA and protein expression of insulin-like factor 3 (INSL3) in the Leydig tumor cells (MA-10) of mice and the level of testosterone secreted from MA-10 cells.Methods The MA-10 cells of mice,used as a cellular model,were exposed to DBP and MBP.The content of testosterone in the supernatant medium was measured by enzyme-linked immunosorbent assay; the mRNA and protein expression levels of INSL3 in MA-10 cells were measured by quantitative PCR and Western Blot.Results Compared with the control group,MA-10 cells showed increased synthesis of testosterone when exposed to low concentrations of DBP and MBP (10-9～10-6 mol/L)and inhibited synthesis of testosterone when exposed to high concentrations of DBP and MBP (l0-3 mol/L),and the typical two-way effects became more significant as the time went one and the concentrations increased (P＜0.05).Compared with the control group,MA-10 cells showed significantly lower mRNA and protein expression levels of INSL3 when exposed to 10-6 and 10-4 mol/L DBP (P＜0.05); MA-10 cells showed increased protein expression of INSL3 when exposed to 10-7 mol/L MBP,and the mRNA and protein expression levels of INSL3 decreased as the concentration of MBP increased.Conclusion DBP and MBP can inhibit the secretion of testosterone from MA-10 cells at high concentrations,but stimulate the secretion of testosterone at low concentrations.Both DBP and MBP have inhibitory effects on the mRNA and protein expression of INSL3 in MA-10 cells. Key words: Dibutyl phthalate;  Monobutyl phthalate;  Leydig tumor cells of mice;  Testosterone;  Insulin-like factor 3