Exposing pregnant mice to low doses of the chemical tributyltin（三丁基锡） -- which is used in marine¹ hull²（船体，外壳） paint and PVC plastic -- can lead to obesity³ for multiple generations without subsequent exposure, a UC Irvine study has found. After exposing pregnant mice to TBT in concentrations similar to those found in the environment, researchers saw increased body fat, liver fat and fat-specific gene⁴ expression in their "children," "grandchildren" and "great-grandchildren" -- none of which had been exposed to the chemical.

 

These findings suggest that early-life exposure to endocrine（内分泌，激素）-disrupting compounds such as TBT can have permanent effects of fat accumulation without further exposure, said study leader Bruce Blumberg, UC Irvine professor of pharmaceutical⁵ sciences and developmental & cell biology. These effects appear to be inherited without DNA⁶ mutations occurring.

 

The study appears online January 15 in Environmental Health Perspectives, a publication of the National Institute for Environmental Health Sciences.

 

Human exposure to TBT can occur through PVC plastic particles in dust and via leaching⁷（沥滤） of the chemical and other related organotin（有机锡） compounds from PVC pipes and containers.

 

Significant levels of TBT have been reported in house dust -- which is particularly relevant for young children who may spend significant time on floors and carpets. Some people are exposed by ingesting seafood⁸ contaminated with TBT, which has been used in marine hull paint and is pervasive⁹（普遍的） in the environment.

 

Blumberg categorizes TBT as an obesogen, a class of chemicals that promote obesity by increasing the number of fat cells or the storage of fat in existing cells. He and his colleagues first identified the role of obesogens in a 2006 publication and showed in 2010 that TBT acts in part by modifying the fate of mesenchymal stem cells during development, predisposing（素因性的） them to become fat cells.

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