Effect Of Maternal BDE-209 Exposure On Offspring's Development Of Articular Cartilage

Objective:To evaluate the effect of BDE-209(brominated diphenyl ethers-209) on the offspring's development of the articular cartilage(AC) through the female wistar rats exposed before pregnancy.Methods:Twenty female wistar rats were divided into two groups which include ten rats in each groups random.Peanut oil suspensions of BDE-209 was given in doses of 1500mg/kg.d by oral gavage for the experiment group,the control group was given the same capacity of pure peanut oil at the same condition.After thirty days,the female with the male rats at a proper propotion,affirm the delivery and then end of oral gravage. 21 days later,measure the body length of neonatal rats and recording.The neonatal rats were killed and knee joint were obtained,HE staining and detecting the thickness of growth plate cartilage(GPC).Chondrocyte apoptosis was detected by teminal deoxynucleotidyl transferase biotin-dUTP nick end labeling(TUNEL) method,The expression of typeⅡcollagen were stained by immunohistochemistry.Results:No significant was observed between the two groups in appearance teratism of the neonatal rats.The average body length in experiment group(17.55±1.58cm),the average body length in control group(19.60±1.09cm) There was significant different between the two groups in the of the neonatal rats(P=0.000＜0.01) after 21 days(P＜0.05),The average body quality in experiment group(33.77±5.81g),The average body quality in control group(34.65±6.15g),There was no significant different between the two groups(P=0.646＞0.05).the thickness of growth plate cartilage in experiment group(331.53±31.83um) was larger than the control group (282.02±21.10um)(P=0.000＜0.01).In the superficial and middle zone of articular cartilage,the positive percentages of chondrocyte apoptosis stained of experiment group(superficial zone 2.05±1.10;middle zone 24.05±5.73) were higherthan the control group(superficial zone 1.25±0.91;middle zone 13.65±3.01)(superficial zone P=0.017＜0.05;middle zone P=0.000＜0.01),but ine the deep zone of articular cartilage,the positive percentages of chondrocyte apoptosis was decrease and there was different between groups(P=0.017＜0.05)(experiment group4.25±3.39; control group 7.50±4.75),at the same time,in the superficial and middle zone of articular cartilage,the The expression of typeⅡcollagen in control group(superficial zone0.216±0.058;middle zone0.204±0.057) was higher than the experiment group(superficial zone 0.166±0.045;middle zone 0.169±0.038)(superficial P=0.004＜0.01;middle P=0.027＜0.05),in the deep zone,the experiment group(0.163±0.049),the control group (0.151±0.049),ther were no different obviousily(P=0.445＞0.05).Conclusion:The maternal BDE-209 exposure during the pregnancy lead to the body length of neonatal rats decrease and the chondrocytes in proliferate zones and hypertrophic zones of growth plate cartilage(GPC) in limbs are excessively obstacle result in osteomalacia.