.contact us |.about us
Home BizChina Newsphoto Cartoon LanguageTips Metrolife DragonKids SMS Edu
news... ...
             Focus on... ...
   

Study links smoking with infertility and early menopause
( 2001-07-16 10:02 ) (7 )

Women who smoke are running the risk of becoming infertile and inducing an early menopause, according to the latest US scientific report to investigate a link already suspected by researchers.

"We've uncovered a mechanism to explain why premature ovarian failure occurs following exposure to toxic chemicals in the environment," the head of the study at Boston's Massachusetts General Hospital says in the report to be published in the August issue of Nature Genetics.

"We've correlated this (the earlier menopause in female smokers) with exposure to a class of chemicals in tobacco smoke that accelerate the death of egg cells in the ovaries," said Jonathan Tilly.

The research adds two more serious medical effects to a catalogue of illnesses and diseases scientifically proven to be caused by smoking, the study says.

Research carried out on mice confirms the long suspected link between female infertility and a class of toxic chemicals known as polycyclic aromatic hydrocarbons (PAHs), which are present in tobacco smoke and cause the destruction of eggs in the ovaries.

The toxic chemicals are also released into the environment by fossil fuel combustion.

These chemicals bind to a receptor inside egg cells of the ovaries causing the release of a gene which then sets off a suicide command ordering the egg to undergo programmed cell death.

But eggs from mice engineered to lack either the receptor or the gene were not affected by the toxic chemicals in the same way, showing the importance of both the gene and the receptor in premature ovarian failure.

Scientists then grafted tissue from human ovaries under the skin of mice, to prove that the research carried out on mice would have similar effects on humans.

When the mice were given an injection of the toxic compound, researchers reported a striking increase in degenerating eggs and programmed cell death in the human ovarian tissues, in the same way that they observed in mice ovaries.

"The data strongly support the hypothesis that the early onset of menopause in women smokers is caused, at least in part, by the actions of tobacco smoke-derived PAHs (toxins) in human oocytes" -- eggs before they mature, Tilly says.

He added that he hopes the technique of grafting human tissue onto the mice will allow for further research on the effect of other potential biohazards and drugs on the health of women's eggs.

The report will be available online from Monday.

 
   
 
   

 

         
         
       
        .contact us |.about us
  Copyright By chinadaily.com.cn. All rights reserved  
主站蜘蛛池模板: 国产婷婷成人久久av免费高清| 性色AV一区二区三区夜夜嗨| 亚洲宅男精品一区在线观看| a毛片免费观看完整| 日本大片在线看黄a∨免费| 免费吃奶摸下激烈视频| 手机看片福利日韩国产| 天天夜碰日日摸日日澡| 久久精品国产亚洲AV麻豆~| 精品国自产拍天天拍2021| 国产妇女馒头高清泬20p多| 182tv精品视频在线播放| 多人伦精品一区二区三区视频| 久久精品中文字幕大胸| 第一福利社区导航| 国产一区二区福利久久| 91麻豆精品国产片在线观看| 日本高清中文字幕在线观穿线视频 | 日本xxxxx高清视频| 国产精品特级露脸AV毛片| 久久久亚洲精品视频| 没带罩子让老师捏了一节课| 国产乱码精品一区二区三| 欧美性bbwbbw| 国产精品影音先锋| 一本加勒比hezyo东京re高清| 无码人妻精品一区二区三区久久 | 色先锋影音资源| 国产美女久久精品香蕉69| 中文字幕国产综合| 日本天堂在线视频| 亚洲最新视频在线观看| 精品日本一区二区三区在线观看| 国产精品久久久| 一级做a爰片毛片| 日韩午夜免费视频| 亚洲AV无码乱码国产精品| 欧美人与zoxxxx另类| 亚洲国产欧美精品| 欧美性猛交xxxx黑人| 亚洲国产精久久久久久久|