摘要
为探讨有机磷酸酯阻燃剂磷酸三(1-氯-2-丙基)酯(TCPP)和间苯二酚双(二苯基)磷酸酯(RDP)对水生生物的内分泌干扰机制及性别差异化响应,以斑马鱼成鱼为模式生物,开展浓度分别为96h-LC50的1%(400µg/L)和1‰(40µg/L)的暴露实验.结果表明:TCPP和RDP暴露对斑马鱼雌/雄个体的肥满度、脑体指数和性腺体指数均未引发显著变化,但乙酰胆碱酯酶活性在所有暴露组均显著下降(7.80%~31.31%,P<0.01),其中雌鱼对TCPP的响应更为敏感.同时,各暴露组斑马鱼丙二醛水平升高(34.37%~166.25%),谷胱甘肽含量下降(29.51%~58.64%),显示TCPP和RDP均诱导了氧化应激反应.进一步研究发现,TCPP和RDP暴露显著扰动斑马鱼下丘脑-垂体-甲状腺轴(HPT)功能,导致甲状腺激素三碘甲状腺原氨酸水平下降、甲状腺素水平升高,且雌鱼受影响更为显著(P<0.01,P<0.05).基因表达分析显示,TCPP和RDP显著抑制雌鱼体内HPT轴相关基因crh和tshβ的表达(P<0.05),而雄鱼相关基因未见明显变化,进一步证实两种OPEs对HPT轴的干扰存在性别依赖性.此外,TCPP和RDP暴露干扰雌/雄斑马鱼性激素水平,其中雄鱼体内睾酮(T)水平显著升高,雌二醇(E2)水平显著降低(P<0.001),同时下丘脑-垂体-性腺轴(HPG)关键基因表达也受到影响,其中cyp19ala下调,抑制T向E2的转化,导致E2水平降低,影响雄鱼的精子生成及运动能力.综上,TCPP和RDP暴露均可通过HPT轴和HPG轴引发显著的内分泌干扰,且干扰具有明显的性别依赖性.本研究强调在环境污染物生态毒性评价中系统考虑性别差异的重要性.
To elucidate the endocrine-disrupting mechanisms and sex-dependent responses of organophosphate flame retardants(OPEs),tris(1-chloro-2-propyl)phosphate(TCPP)and resorcinol bis(diphenyl)phosphate(RDP),adult zebrafish(Danio rerio)were employed as a model organism.Exposure experiments were conducted at two concentrations corresponding to 1%(400μg/L)and 1‰(40μg/L)of the 96h median lethal concentration(LC50).The results showed that neither TCPP nor RDP exposure caused significant changes in body condition factor,brain somatic index(BSI),or gonad somatic index(GSI)in either female or male zebrafish.However,acetylcholinesterase(AChE)activity was significantly inhibited in all exposed groups by 7.80%~31.31%(P<0.01),with females exhibiting greater sensitivity to TCPP.Meanwhile,malondialdehyde(MDA)levels were significantly elevated(34.37%~166.25%),whereas glutathione(GSH)contents were markedly reduced(29.51%~58.64%)indicating that both TCPP and RDP induce oxidative stress in zebrafish.Exposure to TCPP and RDP significantly disrupted the function of the hypothalamic-pituitary-thyroid(HPT)axis,as evidenced by decreasing triiodothyronine(T3)levels and increasing thyroxine(T4)levels,with more pronounced effects observed in females(P<0.01,P<0.05).Gene expression analysis further revealed that TCPP and RDP significantly downregulated the HPT axis-related genes crh and tshβin females(P<0.05),whereas no significant alterations were detected in males,confirming a clear sex-dependent disruption of the HPT axis by these OPEs.In addition,TCPP and RDP exposure disturbed sex hormone homeostasis in zebrafish.In males,testosterone levels were significantly increased,while estradiol levels were markedly decreased(P<0.001).Consistent with these hormonal alterations,the expression of cyp19a1a,a key gene involved in the hypothalamic-pituitary-gonadal(HPG)axis,was significantly downregulated,inhibiting the conversion of testosterone to estradiol.This disruption may impair spermatogenesis and sperm motility in males zebrafish.Overall,TCPP and RDP exposure induced pronounced endocrine disruption via interfering with both the HPT and HPG axes,with distinct sex-dependent effects.This study underscores the importance of considering sex differences in the toxicological evaluation.
作者
苏可欣
卢婷
王鑫伟
李梅
SU Ke-xin;LU Ting;WANG Xin-wei;LI Mei(State Key Laboratory of Water Pollution Control and Green Resource Recycling,School of Environment,Nanjing University,Nanjing 210023,China)
出处
《中国环境科学》
北大核心
2026年第2期1015-1027,共13页
China Environmental Science
基金
国家自然科学基金资助项目(22576100,52192682,22176094)。
