[Effects on serum hormones of rats exposed to subchronic low-dose arsenic].

Objective: To study the effect on endocrine system of SD rats exposed to low-dose arsenic.
Methods: A subchronic test on rats which were divided into five groups randomly( the control group, 0. 05, 0. 1, 0. 2, 0. 4 μg / m L), 20 rats each group, half male and female. A total of 200 rats were allowed to acclimate for 1 week and their hormones level were measured by RIA method after 110 and 194 days.
Results: The hormones level of rats was disordered in different groups. The T level of male rats exposedto arsenic for 110 days were( 4. 80 ± 4. 26), ( 4. 54 ± 3. 31), ( 1. 27 ± 1. 51), ( 1. 93 ±2. 23) and( 4. 83 ± 2. 31) ng / m L( P = 0. 05), respectively. The T4 level of each female group were( 40. 20 ± 7. 10), ( 40. 85 ± 8. 66), ( 46. 49 ± 8. 52), ( 44. 66 ± 11. 83) and( 26. 80 ± 8. 12) ng /m L, compared with control group, 0. 4 μg /m L group decreased obviously( P < 0. 05). Meanwhile, their Cort level of each group were( 312. 10 ±10. 61), ( 333. 15 ± 15. 73), ( 341. 13 ± 19. 25), ( 342. 59 ± 25. 96) and( 314. 84 ±16. 76) ng / m L, and the 0. 05, 0. 1 and 0. 2 μg / m L groups were significantly increased( P < 0. 05). Furthermore, the T4 level of male groups exposed to arsenic for 194 days were( 23. 06 ± 5. 54), ( 33. 18 ± 5. 29), ( 34. 23 ± 4. 15), ( 37. 19 ± 4. 13) and( 39. 92± 6. 27) ng / m L, respectively. Compared with control group, all experimental group significantly increased( all P < 0. 05). Additionally, the T3 level of female group were( 0. 84 ± 0. 12), ( 0. 89 ± 0. 14), ( 0. 83 ± 0. 15), ( 0. 96 ± 0. 16) and( 0. 75 ± 0. 11)ng / m L, and 0. 2 μg / m L group obviously increased( P < 0. 05). Obvious change of hormone had not been found in other group exposed to subchronic low-dose arsenic( all P> 0. 05).
Conclusion: Subchronic low-dose arsenic exposure have slight endocrine effects on SD rats.