[내분비 교란물질] 비스페놀A, 허용량 이하도 해롭다”

건강과대안 — Mon, 16 Jul 2012 10:56:26 +0000

비스페놀A, 허용량 이하도 해롭다”
서울대의대 동물실험서 간기능저하 등 관찰

연합뉴스 | 김길원

입력 2012.07.16 06:14 | 수정 2012.07.16 08:55

(서울=연합뉴스) 김길원 기자 = 내분비계 교란물질인 ‘비스페놀A(Bisphenol A)’는 허용량 이내의 적은 양에 노출돼도 해로울 수 있음을 보여주는 동물실험 결과가 나왔다.

서울대의대 내과 박영주 교수팀은 생쥐 45마리를 대상으로 비스페놀A를 투여하지 않은 그룹, 저용량(몸무게당 0.05㎎)으로 투여한 그룹, 고용량(몸무게당 1.2mg)으로 투여한 그룹 등 3개그룹으로 나눠 관찰했다. 그 결과, 낮은 용량에서도 세포 내 미토콘드리아의 변형과 간기능 저하를 관찰했다.

비스페놀A는 플라스틱과 에폭시, 레진 등의 원료물질로 아기 젖병이나 음식·음료수를 보관하는 캔, 치아 밀봉제 등에 들어 있다. 음식이나 음료수를 섭취하다가 소량의 비스페놀A에 장기간 지속적으로 노출되는 셈이다.

이 때문에 비스페놀A는 사람의 혈액과 소변은 물론 임산부의 태반이나 양수에서도 검출된다. 현재 체중 60㎏인 성인의 비스페놀A 하루 섭취 허용량은 3㎎이다.

지금까지 비스페놀A는 여성호르몬과 비슷한 성질이 있어서 주로 생식기관에 영향을 미치는 것으로 알려져 왔다. 그러나 최근에는 간, 췌장, 갑상선 등 다양한 장기에 영향을 미친다는 보고가 잇따르고 있다.

미국의 국민건강영양조사(NHANES)에서는 비스페놀A에 많이 노출된 사람일수록 심혈관 질환과 당뇨병, 간기능 이상 등의 문제가 많았다는 분석이 나온 바 있다.

이번 연구결과도 적은 양의 비스페놀A가 이런 부작용을 가져올 수 있음을 뒷받침한다.

실험 결과를 담은 논문을 보면 저용량(몸무게당 0.05㎎)의 비스페놀A를 투여한 쥐들도 시간이 지날수록 간수치가 점차 상승해 24시간이 지나자 정상 쥐들보다 간수치가 1.5~2배가량 높아졌다.

생쥐의 간세포를 전자현미경으로 관찰한 결과, 간세포 안에서 미토콘드리아의 모양이 비정상적으로 변화했으며 미토콘드리아도 기능이 저하됐다는 게 연구팀의 설명이다.

이와 함께 간세포에서 산화스트레스 및 염증과 관련된 지표들이 상승했고, 이런 현상은 미토콘드리아의 기능이상과 밀접한 관련이 있는 것으로 연구팀은 분석했다.

연구팀은 16일 “세포실험에서도 간세포(HepG2)에 비스페놀A를 직접 극미량 처리하자 미토콘드리아의 모양이 비정상적으로 변하고, 기능이 저하되는 게 확인됐다”면서 “허용량 이하의 비스페놀A도 유해성이 관찰된 만큼 주의가 필요하다”고 말했다.

bio@yna.co.kr

[유방암] 비스페놀 A(BPA), 원숭이 실험에서 유방암 위험 증가

건강과대안 — Wed, 30 May 2012 01:35:32 +0000

음식을 담는 플라스틱 용기의 원료로 사용되고 있는 비스페놀 A(BPA)가 원숭이 실험에서 유방암의 발생에 영향을 끼치는 것으로 나타났다는 워싱턴 주립대학과 터프츠 대학 공동연구팀의 연구결과를 소개하고 있는 데일리메일 기사입니다.

New breast cancer fears: Chemical widely used in plastic packaging affects mammary gland development in monkeys

By Ted Thornhill

출처 : 데일리메일 19:00 GMT, 7 May 2012 | UPDATED: 19:03 GMT, 7 May 2012
http://www.dailymail.co.uk/health/article-2140885/New-breast-cancer-fears-BPA.html?ITO=1490

Cancer fears have grown over a chemical widely used in plastic packaging and food-can linings after new research showed that it affected the development of monkey breasts.

Various studies have linked Bisphenol A (BPA) to breast cancer – and now teams at Washington State University and Tufts University have added weight to these findings.

They found that foetal exposure to the plastic additive alters mammary gland development in primates.

Cause for concern: BPA exposure affected breast development in rhesus macaques

THE POTENTIALLY DEADLY CHEMICAL IN COMMON USE

Bisphenol A (BPA) is an organic compound used in a wide variety of products, mostly plastics.

It is controversial because many studies have shown that it has adverse health affects, while others say it is not a concern.

The World Health Organisation has not limited or banned the use of the chemical in industry, but the EU and Canada has banned its use in baby bottles. In 2010 Canada became the first country to declare BPA a toxic substance.

Various studies have linked BPA to prostate and breast cancer, while another showed it can affect brain function in lab rats.

A 2009 study on Chinese workers in BPA factories found that they were four times more likely to report erectile dysfunction and reduced sexual desire than workers with no heightened BPA exposure.

Lead author Patricia Hunt said: ‘Previous studies in mice have demonstrated that low doses of BPA alter the developing mammary gland and that these subtle changes increase the risk of cancer in the adult.

‘Some have questioned the relevance of these findings in mice to humans. But finding the same thing in a primate model really hits uncomfortably close to home.’

For the research the structure of newborn mammary glands from BPA-exposed and unexposed female rhesus macaques were compared.

Pregnant monkeys were fed a piece of fruit containing a small amount of BPA each day during the gestational period corresponding to the human third trimester of pregnancy, resulting in blood levels of BPA comparable to those of many humans today.

The researchers found that, at birth, the density of mammary buds was significantly increased in BPA-exposed monkeys, and the overall development of the mammary gland was more advanced compared to unexposed monkeys.

Previous studies have shown that exposing rodents to tiny amounts of BPA can alter mammary gland development, leading to pre-cancerous and cancerous lesions when the animals exposed in utero reach adult age.

The researchers said the primate research makes them confident that the rodent mammary gland is a reliable model to study developmental exposures to chemicals like BPA that disrupt a mammal’s estrogen activity.

Tufts University School of Medicine researcher Ana Soto said: ‘This study buttresses previous findings showing that foetal exposure to low xenoestrogen levels causes developmental alterations that in turn increase the risk of mammary cancer later in life.

‘Because BPA is chemically related to diethylstilbestrol, an estrogen that increased the risk of breast cancer in both rodents and women exposed in the womb, the sum of all these findings strongly suggests that BPA is a breast carcinogen in humans and human exposure to BPA should be curtailed.’

The research appears in the latest Proceedings of the National Academies of Sciences.

=====================

Andrew P. Tharp,
Maricel V. Maffini,
Patricia A. Hunt,
Catherine A. VandeVoort,
Carlos Sonnenschein,
and Ana M. Soto

Bisphenol A alters the development of the rhesus monkey mammary gland PNAS 2012 109 (21) 8190-8195; published ahead of print May 7, 2012, doi:10.1073/pnas.1120488109

http://www.pnas.org/content/109/21/8190.abstract?sid=9042efe9-16d9-4b47-8689-8f589d06f86d

Bisphenol A alters the development of the rhesus monkey mammary gland

+ Author Affiliations

^aDepartment of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, MA 02111;
^bSchool of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, WA 99164; and
^cDepartment of Obstetrics and Gynecology and California National Primate Research Center, University of California, Davis, CA 95616

Edited* by Joan V. Ruderman, Harvard Medical School, Boston, MA, and approved April 2, 2012 (received for review January 3, 2012)

Abstract

The xenoestrogen bisphenol A (BPA) used in the manufacturing of various plastics and resins for food packaging and consumer products has been shown to produce numerous endocrine and developmental effects in rodents. Exposure to low doses of BPA during fetal mammary gland development resulted in significant alterations in the gland’s morphology that varied from subtle ones observed during the exposure period to precancerous and cancerous lesions manifested in adulthood. This study assessed the effects of BPA on fetal mammary gland development in nonhuman primates. Pregnant rhesus monkeys were fed 400 μg of BPA per kg of body weight daily from gestational day 100 to term, which resulted in 0.68 ± 0.312 ng of unconjugated BPA per mL of maternal serum, a level comparable to that found in humans. At birth, the mammary glands of female offspring were removed for morphological analysis. Morphological parameters similar to those shown to be affected in rodents exposed prenatally to BPA were measured in whole-mounted glands; estrogen receptor (ER) α and β expression were assessed in paraffin sections. Student’s t tests for equality of means were used to assess differences between exposed and unexposed groups. The density of mammary buds was significantly increased in BPA-exposed monkeys, and the overall development of their mammary gland was more advanced compared with unexposed monkeys. No significant differences were observed in ER expression. Altogether, gestational exposure to the estrogen-mimic BPA altered the developing mammary glands of female nonhuman primates in a comparable manner to that observed in rodents.

Footnotes

↵¹A.P.T. and M.V.M. contributed equally to this work.

↵²To whom correspondence should be addressed. E-mail: ana.soto@tufts.edu.

Author contributions: P.A.H. and A.M.S. designed research; A.P.T., M.V.M., and C.A.V. performed research; A.P.T., M.V.M., C.S., and A.M.S. analyzed data; and A.P.T., M.V.M., C.S., and A.M.S. wrote the paper.

The authors declare no conflict of interest.