| Atrazine (ATR), discovered by the Swiss H. Geising and E. Kenusili in1952, wasdevelopmented by the Swiss Geigy company in1958, and was put into production in1959.Due to its excellent insecticidal function, it is now developed into the largest herbicide inthe world. At the beginning of the1970s, ATR was producted and widely used in China. Asone of the most widely used herbicides worldwide, ATR has caused a series of toxicologicaland environmental problems. Many specialists has done a lot of researches about toxicologyaspects of ATR, and the experimental subjects of the researches are relate to the naturalenvironment, aquatic plants, aquatic animals, mammals, etc. Some of the experiments try topush the results down to the human, and try to establish a relationship between ATR anddiseases by these studies. In2012, using female rats as experimental object, James WSimpkins explore the atrazine exposure was associated with female breast cancer. Combinedwith its biological rationality and epidemiological research evidence, the researchersobserved the experiment and showed the connection between atrazine exposure and femalebreast cancer. More and more research results show that, atrazine may cause infection, tumorand other diseases. However, there is no clear experimental results which can illustrate themechanism.This study sought to investigate the effects of ATR on the immune system of mice.Four-week-old female C57BL/6mice were treated with0,5,25and125mg/kg ATR for28days. On day29, blood was collected and the spleen was harvested to detect lymphocytetransformation, natural killer (NK) cell activity, cellular phenotypes, and cytokines. Resultsindicated that the thymus and spleen weights decreased after ATR treatment, and the spleenwas found to be more sensitive to ATR than the thymus. Decreases in lymphocytetransformation and NK cell activity were also observed in mice treated with25mg/kg ATRand125mg/kg ATR compared to the control group. In addition, there were also alterationsof lymphocyte phenotypes in the spleen, and the percentages of CD3+and CD4+cellsdecreased in mice treated with25mg/kg ATR and125mg/kg ATR compared to the controlgroup. Moreover, serum interleukin-4level decreased significantly after treatment with25mg/kg and125mg/kg ATR, but ATR did not affect the expression of interleukin-2, interferon-γ, and tumor necrosis factor-α. These results suggest that ATR may have induceddamage in spleen cells. The spleen is the largest lymphoid organ of the body. As a storage ofthe blood which is one the important function of spleen, spleen increased blood volumeunder stress. On the other hand, the important role of the spleen is generating lymphocytes,filtering the pathogens in the blood. Spleen injury means that human body cell immunefunction is restrained, which may cause the risk of infection, and cancer increase. As ATR isan environmental contaminant, its immunosuppressive action raises concerns that it maypotentiate clinical conditions such as tumors, inflammation, and infections. Thus, it needs tobe carefully monitored and studied.This study found that ATR interferes with immune function by inducing degenerativechanges in the spleen, inhibiting the proliferation of T lymphocytes and NK cell cytotoxicactivity, decreasing the percentage of CD3+and CD4+T lymphocytes, and reducing theserum levels of IL-4. Results indicated that ATR may be associated with inflammation,infections, and other diseases. But, further studies are needed to elucidate the exactmechanisms underlying the deleterious effects of ATR on the immune system and toinvestigate the effects of prolonged exposure to ATR under natural conditions. |
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