OBJECTIVETo investigate the DNA damage of splenic lymphocytes in pregnant mice exposed to carbon disulfide (CS2) in the implantation phase and to explore the mechanism of abnormal implantation induced by CS2 from the perspective of immune injury.

METHODSMice were exposed to CS2 at different doses or at different time points in the implantation phase to establish model 1 and model 2. For model 1, mice were assigned to four groups to receive a single intraperitoneal injection of low-dose CS2 (0.1 LD50, 157.8 mg/kg), middle-dose CS2 (0.2 LD50, 315.7 mg/kg), and high-dose CS2 (0.4 LD50, 631.4 mg/kg) as well as an equal volume of olive oil (control) on gestational day (GD) 4. For model 2, mice were assigned to four groups to receive a single intraperitoneal injection of CS2 (0.4 LD50, 631.4 mg/kg) or an equal volume of olive oil (control) on GD3, GD4, GD5, and GD6. At the end, single cell suspension of splenic lymphocytes was prepared. Cell viability was measured by trypan blue staining, and the DNA damage of splenic lymphocytes was evaluated by alkaline single cell gel electrophoresis assay.

RESULTSThe middle-dose and high-dose exposure groups showed significantly more DNA damage of splenic lymphocytes than the control group (P < 0.01); there was significant regression relationship between indicators of DNA damage and exposure doses (P < 0.01). The GD3, GD4, GD5, and GD 6 exposure groups showed significantly more DNA damage of splenic lymphocytes than the control group (P < 0.01), and the GD 4 exposure group had the most DNA damage.

CONCLUSIONExposure to CS2 in the implantation phase can induce DNA damage of splenic lymphocytes in pregnant mice, and the DNA damage was aggravated with the increase in CS2 concentration. GD4 may be the sensitive time point for DNA damage of splenic lymphocytes induced by CS2 in pregnant mice.