Researchers from the CEA-iRCM have provided the
first experimental evidence that low concentrations of bisphenol A are
sufficient to negatively affect the testicles in humans. Up until now,
no experimental studies have demonstrated this deleterious effect of
bisphenol A on male reproduction; what few epidemiological studies there
are remain contradictory.
In collaboration with the
Antoine-Béclère hospital in Clamart, the researchers kept human fetal
testes alive in culture dishes for 3 days in the presence or absence of
bisphenol A, in accordance with an original protocol previously
developed by this team. Their results show that exposure of human fetal
testes to bisphenol A reduces the production of testosterone, as well as
another testicular hormone necessary for their descent into the scrotum
during fetal development. A concentration of bisphenol A equal to 2
micrograms per liter in the culture medium is sufficient to induce these
effects. This concentration is equivalent to the average concentration
usually found in the blood, urine and amniotic fluid of the general
population.
Système
de culture des testicules foetaux mis au point par l'équipe de René
Habert. Les testicules découpés en petits fragments sont déposés sur un
filtre au centre d'une boite de culture. Dans une atmosphère appropriée,
ils survivent ainsi pendant plusieurs jours en sécrétant de la
testostérone
Fetal testicle culture system developed by
the team of René Habert. Testicles cut into small fragments are
deposited on a filter at the center of a culture dish. In an appropriate
atmosphere, they can survive and secrete testosterone for several days.
It is known that testosterone produced by the testes during fetal
life causes masculinization of internal and external genitalia; in the
absence of testosterone, these organs would otherwise spontaneously
adopt feminine characteristics. In addition, it is likely that
testosterone plays a role in the development of the testes themselves.
Thus, current exposure to bisphenol A in pregnant women could be one of
the causes of congenital masculinization defects (such as hypospadias
and cryptorchidism) whose frequencies have altogether doubled in 40 years. According to René Habert, “It’s
also possible that bisphenol A is involved in the declining sperm
production and the increased incidence of testicular cancer in adults
observed during the past decades.”