1. Stage II Stage VII Stage V Stage XII

2. 2-Bromopropane (mg/kg/day) Days on test0 1,000 Day 0399.9±32.75 a 397.1±20.23 Day 3405.1±32.66392.4±19.66 Day 7410.9±29.27386.9±19.29** Day 14419.4±29.31391.9±17.24** a Mean±SD (n=10); ** P<0.01 vs control Table 1. Body weight changes of male rats treated with 2-BP for 2 weeks

3. Table 2. Reproductive organ weights of male rats treated with 2-BP for 2 weeks 2-Bromopropane (mg/kg/day) Parameters0 1,000 Testis: left (g) per body weight (%) 1.77±0.119 a 0.42±0.027 1.61±0.064** 0.41±0.024 Testis: right (g) per body weight (%) 1.77±0.158 0.42±0.032 1.63±0.069** 0.42±0.018 Epidydimis: left (g) per body weight (%) 0.66±0.074 0.16±0.026 0.63±0.054 0.16±0.010 Epidydimis: right (g) per body weight (%) 0.68±0.067 0.16±0.024 0.62±0.064 0.16±0.013 Prostates (g) per body weight (%) 0.73±0.126 0.17±0.024 0.62±0.150 0.16±0.037 Seminal vesicles (g) per body weight (%) 1.30±0.120 0.31±0.036 1.13±0.122** 0.29±0.034 a Mean±SD (n=10); ** P<0.01 vs control

4. Table 3. The incidence and severity of histopathological lesions of testis and epididymis in male rats Control Days on test (1,000mg/kg/day) Day 3 Day 7 Day 14 Parameters Grades:0 1 2 3 Testis Atrophy of seminiferous tubules10 0 0 0 9 1 0 06 2 2 0 Exfoliation of spermatogenic cells10 0 0 0 6 2 2 06 3 1 0 Degeneration of spermatogonia10 0 0 02 5 3 00 4 5 17 3 0 0 Decrease of spermatogonia10 0 0 00 4 6 00 0 10 0 Degeneration of spermatocytes10 0 0 00 7 3 00 3 5 24 5 1 0 Decrease of spermatocytes10 0 0 0 0 7 3 00 0 4 6 Multinuclear giant cells10 0 0 09 1 0 05 2 2 110 0 0 0 Mature spermatid retention10 0 0 04 6 0 02 3 5 01 2 7 0 Vacuolation of Sertoli cells10 0 0 02 6 2 01 8 1 02 6 2 0 Epididymis Oligozoospermia10 0 0 0 8 2 0 05 3 2 0 Degenerated spermatogenic cells10 0 0 03 7 0 00 7 2 10 3 3 4 Grades are as follows: 0, normal; 1, slight; 2, moderate; and 3, severe change. N=10

5. * CD B * * C ESt RSt PSc SC Sg A Stage V

6. * * MSt C * B D A ZSc Sg SC PSc ESt Stage X

8. Table 4. The number of spermatogenic cells in seminiferous tubules of male rats Days on test (1,000 mg/kg/day) ParametersControlDay 3 Day 7 Day 14 StageSpermatogonia20.2±3.61 a 4.0±3.65**1.9±1.60**2.3±3.22** Ⅱ Pachytene spermatocytes49.4±10.3352.9±7.3840.7±9.885.3±7.47** Round spermatids158.3±18.48147.4±28.17129.2±35.04148.8±16.09 Elongated spermatids153.5±27.75153.9±22.48138.1±28.28148.6±39.73 Sertoli cells18.8±4.2917.4±4.1616.1±4.1515.9±2.02 StageSpermatogonia37.4±4.933.9±3.89**2.1±2.13**2.0±3.62** Ⅴ Pachytene spermatocytes52.5±7.7050.1±9.1945.3±14.9334.0±16.30* Round spermatids153.6±9.49146.4±26.89138.2±36.88150.6±23.39 Elongated spermatids167.3±12.75148.7±32.07152.5±33.48150.5±29.04 Sertoli cells17.5±3.9215.7±1.8915.4±3.0314.9±2.42 a Mean±SD (n=10); *, ** P<0.05, P<0.01 vs control

9. Days on test (1,000 mg/kg/day) ParametersControlDay 3 Day 7 Day 14 StageSpermatogonia2.3±0.67 a 2.1±0.691.8±0.631.9±0.74 Ⅶ Preleptotene spermatocytes38.8±4.1834.3±10.373.0±2.05**4.2±5.65** Pachytene spermatocytes56.4±8.8253.9±6.1250.7±12.2648.0±9.83 Round spermatids151.6±15.87145.4±19.10157.1±30.50136.1±31.61 Elongated spermatids157.0±19.84153.0±32.86146.8±25.26138.0±25.72 Sertoli cells17.8±2.9015.9±5.5514.9±3.0714.6±3.27 StageSpermatogonia3.6±1.352.0±1.152.8±2.151.5±1.51 Ⅻ Zygotene spermatocytes46.9±5.3443.4±2.5120.6±25.07**2.4±5.23** Pachytene spermatocytes61.8±5.3763.6±5.8064.8±13.1360.9±19.16 Elongated spermatids168.7±27.37154.4±15.99153.1±41.31143.0±27.83 Sertoli cells19.7±3.5619.6±3.8716.5±2.2217.1±3.38 a Mean±SD (n=10); *, ** P<0.05, P<0.01 vs control Table 4. Continued

10. D * * * C A SC Sg PSc ESt RSt Stage II B