Objective      To investigate the spermatogenic damage in male mice after continuous exposure to automobile exhaust.       Methods      Twenty male C57BL/6 mice were randomly divided into control and exposed group (n=10). The mice of the exposed group were inflicted with continuous exposure to automobile exhaust

while the animals in the control lived in the same condition as the exposed group. Gas component detector and blood gas analysis were used to determine the hypoxia level between control group and exposure group. Viscera coefficient

HE staining and computer-assisted sperm analysis were used to determine the histology and function between control group and exposure group. Plasma and testicular levels of nitric oxide (NO) and total antioxidant capacity (T-AOC) were compared between the 2 groups.       Results      The composition detection in the device of automobile exhaust found that the contents of oxygen

sulfur dioxide and PM2.5 were consistent from the beginning to end of the exposure. No hypoxia was seen in the exposure group in the blood gas analysis

with no significant difference from the control group (P0.05). There was no obvious differences in the testis and epididymis coefficients between the 2 groups (P0.05). The exposure group had the spermatogenic cells in sparse arrangement

significantly reduced seminiferous layers

vacuolarization and reduced sperm amount within the lumen in the testis. Computer-aided sperm analysis found that exposure group had significantly decreased sperm count and quality

significant different with the control group. The plasma and testicular levels of NO were obviously decreased

while those of T-AOC were increased in the exposure group than the control (both P0.05).       Conclusion      Continuous exposure to automobile exhaust damages the spermatogenesis and sperm function in male C57BL/6 mice

which may be related to the changes in oxidation levels of plasma and testicular tissue.