Sterility in frogs caused by environmental pharmaceutical progestogens

February 16, 2011

Frogs appear to be very sensitive to progestogens, a kind of pharmaceutical that is released into the environment. Female tadpoles that swim in water containing a specific progestogen, levonorgestrel, are subject to abnormal ovarian and oviduct development, resulting in adult sterility. This is shown by a new study conducted at Uppsala University and published today in the scientific journal Aquatic Toxicology.

Many of the medicines that people consume are released into the environment via sewage systems. Progestogens are hormone preparations used in contraceptives, and for menopausal discomfort. Different kinds of progestogens have been identified in waterways in a number of countries. Associate professor Cecilia Berg and doctoral student Moa Kvarnryd at the Department of Environmental Toxicology at Uppsala University have shown that levonorgestrel can cause sterility in female frogs at concentrations not much higher than those measured in the environment. The research group is part of MistraPharma, one of the world's largest research networks focusing on pharmaceuticals and the environment.

"The findings represent important initial evidence that an environmental progestogen can adversely affect frogs," says Cecilia Berg.

Female that swam in water containing low concentrations of levonorgestrel exhibited a greater proportion of immature ovarian egg cells and lacked oviducts, entailing . The African clawed frog (Xenopus tropicalis) served as the . It is during the tadpole stage that development of frog reproductive organs begins. The process is governed by the hormone system. The findings underscore the importance of studying how pharmaceuticals affect animals in our environment, which is one objective of MistraPharma.

"Our findings show that pharmaceuticals other than oestrogen can cause permanent damage to aquatic animals exposed during early life stages," says Cecilia Berg.

Explore further: Frogs with disease-resistance genes may escape extinction

More information: Aquatic Toxicology doi:10.1016/j.aquatox.2011.02.003

Related Stories

Frogs with disease-resistance genes may escape extinction

July 16, 2008

As frog populations die off around the world, researchers have identified certain genes that can help the amphibians develop resistance to harmful bacteria and disease. The discovery may provide new strategies to protect ...

Study: Range of pharmaceuticals in fish across US

March 25, 2009

(AP) -- Fish caught near wastewater treatment plants serving five major U.S. cities had residues of pharmaceuticals in them, including medicines used to treat high cholesterol, allergies, high blood pressure, bipolar disorder ...

Medicine residues may threaten fish reproduction

April 5, 2010

Researchers at Umea University and the Sahlgrenska Academy at the University of Gothenburg, Sweden, have discovered that traces of many medicines can be found in fish that have been swimming in treated waste water. One such ...

Inventions of evolution: What gives frogs a face

January 13, 2011

Zoologists of the University Jena (Germany) analysed the central factor for the development of the morphologically distinctive features of the tadpoles. "We were able to show that the 'FOXN3' most of all influences the development ...

Recommended for you

Male seahorse and human pregnancies remarkably alike

September 1, 2015

Their pregnancies are carried by the males but, when it comes to breeding, seahorses have more in common with humans than previously thought, new research from the University of Sydney reveals.

Parasitized bees are self-medicating in the wild, study finds

September 1, 2015

Bumblebees infected with a common intestinal parasite are drawn to flowers whose nectar and pollen have a medicinal effect, a Dartmouth-led study shows. The findings suggest that plant chemistry could help combat the decline ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.