Branchi Igor, Capone Francesca, Vitalone Annabella, Madia Federica, Santucci Daniela, Alleva Enrico, Costa Lucio G
Istituto Superiore di Sanità, Section of Behavioural Neuroscience, Department of Cell Biology and Neuroscience, Viale Regina Elena 299, 00161 Rome, Italy.
Neurotoxicology. 2005 Mar;26(2):183-92. doi: 10.1016/j.neuro.2004.11.005.
Among the most persistent and bio-accumulative environmental pollutants are the polybrominated diphenyl ethers (PBDEs), a class of chemicals widely used as flame retardants in plastics and textile coating, and the polychlorinated biphenyls (PCBs), previously used as coolants and lubricants in electrical equipment. Monitoring programs revealed high levels of both these classes of compounds in human breast milk, raising concerns for their potential noxious effects on infants. The aim of the present study was to investigate the neurotoxic effects of 2,2',4,4',5-penta BDE (BDE 99: 18mg/kg/day) or Aroclor 1254 (A1254, a PCB mixture: 10mg/kg/day) administration, from gestational day (GD) 6 to postnatal day (PND) 21, on neurobehavioral development in the CD-1 Swiss mouse. In addition, we investigated whether the administration route affects the emergence or the magnitude of the toxic effects of BDE 99 or A1254. In particular, we compared self-administration, consisting in letting the mouse drink spontaneously the compound dissolved in oil from a syringe, with gavage, consisting in force-feeding a substance by a tube inserted in the mouth and then into the stomach, a procedure reported to be stress-inducing. Both compounds induced hyperactivity, though BDE 99 affected activity profile only during adolescence and A1254 mainly at adulthood. Levels of total circulating thyroxine were decreased by both BDE 99 and A1254 administration, though only in the latter group the decrease was statistically significant. These findings suggest a different neurotoxic action exerted by PBDEs and PCBs. An effect of the administration route, independent from the compound administered, was found on thigmotactic behavior and gavage administration affected pup body weight gain only in the A1254 group, suggesting that the stress induced by gavage procedure may either affect results per se or modulate the detrimental action of selected compounds.
多溴二苯醚（PBDEs）和多氯联苯（PCBs）是最具持久性且会生物累积的环境污染物。多溴二苯醚是一类广泛用作塑料和纺织品涂层阻燃剂的化学品，多氯联苯以前则用作电气设备中的冷却剂和润滑剂。监测项目显示，这两类化合物在人母乳中的含量很高，这引发了人们对它们可能对婴儿产生有害影响的担忧。本研究的目的是调查从妊娠第6天到出生后第21天给予2,2',4,4',5-五溴二苯醚（BDE 99：18毫克/千克/天）或Aroclor 1254（A1254，一种多氯联苯混合物：10毫克/千克/天）对CD-1瑞士小鼠神经行为发育的神经毒性作用。此外，我们还研究了给药途径是否会影响BDE 99或A1254毒性作用的出现或程度。具体而言，我们比较了自行给药（即让小鼠自发饮用溶解在油中的化合物，通过注射器摄取）和灌胃给药（即通过插入口腔然后进入胃中的管子强制喂食物质，据报道该过程会引起应激）。两种化合物均会导致多动，不过BDE 99仅在青春期影响活动模式，而A1254主要在成年期产生影响。给予BDE 99和A1254后，总循环甲状腺素水平均下降，不过只有后一组的下降具有统计学意义。这些发现表明多溴二苯醚和多氯联苯具有不同的神经毒性作用。发现给药途径的影响独立于所给予的化合物，对趋触性有影响，并且灌胃给药仅在A1254组中影响幼崽体重增加，这表明灌胃过程引起的应激可能本身会影响结果，或者调节所选化合物的有害作用。
