苯并[a]芘对大鼠自主活动及运动协调能力的影响

Effects of benzo[a]pyrene on autonomic activity and motor coordination in rats

目的探讨苯并[a]芘(B[a]P)亚慢性染毒对大鼠自主活动及运动协调能力的影响。方法选取30只雄性SD幼鼠,鼠龄3~4 d,随机分为空白组,溶剂组(1.00 m L/kg植物油),B[a]P染毒低剂量组(0.02 mg/kg)、中剂量组(0.20 mg/kg)及高剂量组(2.00 mg/kg),每组6只。适应饲养环境后按相应浓度持续灌胃7周。染毒结束后测量SD大鼠体质量变化。通过记录其在旷场实验中的爬行总格子数、直立次数和粪便颗粒数,以及在足迹实验中的后跟脚印轨迹等相应指标,评估SD大鼠自主活动及运动协调能力。结果染毒结束后,B[a]P各剂量染毒组SD大鼠生长发育迟缓,表现为体质量均明显低于空白组和溶剂组,爬行总格子数及直立次数较空白组和溶剂组明显增加,差异均有统计学意义(P<0.05);而五组大鼠在足迹实验中步宽、步长、步态及角度变化4项参数指标比较,差异均无统计学意义(P>0.05)。结论B[a]P可抑制SD幼鼠的生长发育,促进其自主活动,但对其运动协调能力作用不明显。

Objective To explore the effect ofsubchronic exposure to benzo[a]pyrene（B[a]P） on autonomic activity and motor coordination in rats. Methods Thirty male juvenile rats, aged 3-4 d,were randomly divided into the blank group, solvent group （1.00 mL/kg plant oil）, B [a]P low-dose group （0.02 mg/kg）, B [a]P medium-dose group （0.20 mg/kg） and B [a]P high-dose group （2.00 mg/kg ）, 6 cases in each group. After acclimatizing the feeding environment, the rats were intragastrically administrated for 7 consecutive weeks according to corresponding concentration. After exposure to toxicant, the body weight of rat was measured. The open field test and foot printing test were conducted to evaluate the autonomic activity and motor coordination of rats, respec- tively. The total number of crawling lattice, up-right times and fecal particles number in the open field test were recorded. Mean- while, the heel footprints track in the foot printing test were also recorded.＇4~e^sults After exposure to toxicant, the growth and de- velopment of SD rats in each contamination group were delayed ,which showed that the body weight of each contamination group was significantly lower than that in the blank group and the total number of crawling lattice and upright times in each contamina- tion group was significantly increased when compared with the blank group and the solvent group, the difference was statistically significant （P〈0.05）. However, there were no statistically significant differences in the step width, step size, gait changes and an- gle changes among the five groups （P〉0.05）. Conclusion B [a]P can inhibit the growth and development of juvenile rats and promotes their autonomic activity, but has not obvious effect on the motor coordination.