OBJECTIVETo explore the effects of p,p'-DDE and beta-BHC on the apoptosis of Sertoli cells in vitro via activation of Caspase.

METHODSSertoli cells were treated in vitro for 24 hours with a serial concentrations of p,p'-DDE (10, 30 and 50 micromol/L), beta-BHC (10, 30 and 50 micromol/L) and p,p'-DDE + beta-BHC (10, 30 and 50 micromol/L). The inhibitory group was first treated with 100 micromol/L Caspase-3 inhibitor Ac-DEVD-CHO treating for 2 hours before 50 micromol/L p, p'-DDE + 50 micromol/L beta-BHC 24 hours-treatment. The vitality of Sertoli cells was determined by MTT and the apoptosis rate was measured by AO/EB double fluorescence staining. The expressions of Caspase-3, Caspase-8 and Caspase-9 were determined by RT-PCR.

RESULTSAverage optical density (A) values were 0.498 +/- 0.039, 0.481 +/- 0.065, 0.397 +/- 0.032 and 0.286 +/- 0.049 in p,p'-DDE groups (10, 30, 50 and 70 micromol/L), and 0.518 +/- 0.103, 0.490 +/- 0.060, 0.454 +/- 0.054 and 0.302 +/- 0.030 in beta-BHC groups (10, 30, 50 and 70 micromol/L). In the mixture-treated groups (10, 30 and 50 micromol/L), the average A values were 0.483 +/- 0.048, 0.473 +/- 0.058 and 0.337 +/- 0.052. Compared with the solvent control group (0.527 +/- 0.022) , 50 micromol/L group of p, p'-DDE, beta-BHC or their mixture caused a significant decrease of Sertoli cell viability (t values were 4.599, 2.716, 6.537 respectively, P < 0.05). AO/EB double fluorescence staining analysis showed that apoptosis rates of Sertoli cells were significantly increased with all treated groups. The expressions of Caspase-3, Caspase-8 and Caspase-9 were upregulated as the concentrations of p,p'-DDE, beta-BHC and their mixture were increased.

CONCLUSIONp,p'-DDE, beta-BHC and their mixture could induce the apoptosis of Sertoli cells in vitro which was associated with activation of Caspase-3 mediated by cleavage of Caspase-8 and Caspase-9.