亲代燃煤型氟中毒大鼠对子代牙齿发育的影响

The influence of parental generation coal-burning-borne fluorosis on tooth development of their offspring

目的探讨亲代大鼠摄入燃煤来源过量氟对仔鼠牙齿发育的影响。方法模拟燃煤型氟中毒病区燃煤方式，复制高氟空气环境，病区煤烘玉米制作含氟饲料。将48只SD大鼠采用随机数字表法按雌雄比1：1分为4组，每组12只。染氟组置于高氟空气中，并分别饲以含氟量为40、25、10mg／kg的饲料（高、中、低氟组），对照组置于普通空气中并饲以普通饲料，8周后合笼交配，观察仔鼠牙齿萌出时间，并在出生后21d（哺乳期）观察仔鼠氟斑牙发病情况、牙齿长度和牙氟含量。结果高氟组、中氟组[（6．83±0．94）、（6．25±1．06）d]仔鼠较对照组[（5．34±0．89）d]牙齿萌出时间晚（P均〈0．01）。21d时，高氟组、中氟组仔鼠下切牙可观察到明显氟斑牙症状；与对照组[（5．21±0．19）mm，（223．00±14．08）μg／kg]比较，高氟组、中氟组仔鼠牙冠长度[（4．83±0．22）、（4．96±0．25）mm]减小（P〈0．01或〈0．05），牙氟含量[（362．64±20．35）、（289．79±19．18）μg／kg]升高（P均〈0．01）。仔鼠氟斑牙发生率与大鼠染氟剂量呈正相关（r=0．704，P〈0．01）。结论亲代大鼠摄入过量氟会影响仔鼠牙齿发育并引起氟斑牙，且与亲代染氟剂量存在相关性。

Objective To study the influence of parental generation coal-burning-borne fluorosis on tooth development of their offspring. Methods High fluoride air model was established on the basis of burning coal habit of the epidemic areas. Fluoride feed was made of coal drying corn from the epidemic areas. Totally 48 SD rats were randomly divided into 4 groups with male to female ratio of 1 ： 1 by random number table method. Rats in high, middle and low fluoride groups were put in the high fluoride air room and feed food with 40, 25 and 10 mg/kg fluorine, and the control group was put in normal air room and feed normal food. After 8 weeks, rats were mating and parturition. Tooth eruption time of offspring rat was observed; and dental fluorosis incidence, the tooth length and fluorine content were observed at 21 d. Results In high and middle fluoride groups [（6.83 ± 0.94）, （6.25 ±1.06） d], tooth eruption time of offspring rat was later than that of control group [（5.34 ±0.89） d, all P 〈 0.01]. At 21 d, dental fluorosis was observed in the lower incisors of the high and middle fluorine groups; compared with control group [（5.21 ± 0.19） mm, （223.00 ± 14.08） μg/kg], the tooth length was decreased [（4.83 ± 0.22）, （4.96 ± 0.25） mm, P 〈 0.01 or 〈 0.05], and tooth fluoride content was increased [（362.64 ± 20.35）, （289.79 ± 19.18） μg/kg, all P 〈 0.01]. Dental fluorosis incidence of offspring rats was positively correlated with the fluorine dose （r = 0.704, P 〈 0.01）. Conclusion Parental generation rats＇ intaking excessive fluoride can affect offspring rats tooth development and dental fluorosis, which is related to the fluorine dose.