饮水硼暴露对大鼠胸腺生长发育及其激素分泌的影响

Effects of boron supplied with drinking water on development and hormone secretion of thymus in rats

目的研究饮水硼暴露对大鼠胸腺生长发育及其激素分泌的影响。方法将100只初断乳清洁级雄性SD大鼠随机分为10组,分别为对照(蒸馏水)组和5、10、20、40、80、160、320、480、640 mg/L硼染毒组,每组10只。采用自由饮水方式进行染毒,连续染毒60 d。测定大鼠胸腺组织学参数(胸腺皮质厚度、皮质/髓质面积比),检测大鼠胸腺内胸腺素和胸腺生成素的浓度。结果与对照组相比,10、20、40和80 mg/L硼染毒组大鼠胸腺皮质厚度和皮质/髓质面积比均增加,而480和640 mg/L硼染毒组大鼠胸腺皮质厚度和胸腺皮质/髓质面积比均降低,除80 mg/L硼染毒组皮质/髓质面积比外,差异均有统计学意义(P<0.05,P<0.01)。与对照组相比,10、20和40 mg/L硼染毒组大鼠胸腺中胸腺素浓度均增加,而480和640 mg/L硼染毒组胸腺素浓度均降低,仅640 mg/L硼染毒组大鼠胸腺中胸腺生成素浓度降低,差异均有统计学意义(P<0.05,P<0.01)。结论饮水添加适量的硼(10～40 mg/L)对雄性大鼠胸腺生长发育及其激素分泌有较明显的改善作用,而添加高剂量(480、640 mg/L)的硼则会造成不同程度地损伤。

Objective To understand the effects of boron supplied with drinking water on the development and hormone secretion of thymus in rats.Methods A total of 100 weanling and cleaning SD male rats were randomly divided into 10 groups,including control group and 5,10,20,40,80,160,320,480 and 640 mg/L boron exposure groups,10 rats in each group.The control group drank distilled water,the boron exposure groups drank distilled water with 5,10,20,40,80,160,320,480 and 640 mg/L boron respectively,for 60 consecutive days.At the end of treatments,the histological parameters(the thickness of the cortex,the cortex/medulla ratio)of the thymus were measured and the contents of thymosin and thymopoietin were determined in the thymus.Results Compared with the control group,the thickness of the cortex and cortex/medulla ratio were increased in the 10,20,40 and 80 mg/L boron exposure groups,but the thickness of the cortex and cortex/medulla ratio were decreased in the 480 and 640 mg/L boron exposure groups,the differences in each group were statistically significant except for the cortex and cortex/medulla ratio in the 80 mg/L boron exposure group(P<0.05,P<0.01).Compared with the control group,the contents of thymosin was increased in the 10,20 and 40 mg/L boron exposure groups,but decreased in the 480 and640 mg/L boron exposure groups(P<0.05);Only the content of thymopoietin was significantly decreased in the 640 mg/L boron exposure groups,the differences in each group were statistically significant(P<0.05,P<0.01).Conclusion Proper supplementation of boron(10-40 mg/L)in drinking water can obviously improve the development and hormone secretion of thymus in male rats,but higher doses of boron(480 and 640 mg/L)can cause different degrees of injury.