Hormone delays egg development

A group of Dutch scientists has identified a hormone that delays the early stages of egg development in mouse ovaries, reports last week's New Scientist. The researchers, based at Erasmus University in Rotterdam, say that the hormone - called anti-Mullerian hormone (AMH) - could eventually be used to delay the menopause and prevent conditions such as osteoporosis.

AMH is essential for male embryo development in mammals, but is also produced by the cells that surround the growing ovary follicles (the cells and fluid that surround developing eggs). This suggests that in females, AMH plays a role in keeping the number of developing follicles at a constant level, says team leader Axel Themmen. The scientists found that mice lacking the hormone had three times the usual number of developing eggs at the age of four months, but had none left by thirteen months - six months before normal mice stop producing eggs.

Ray Rodgers, of Flinders University, Adelaide, said that if the hormone has a similar 'braking effect' on egg development in humans, it could be used as a drug to delay the menopause. It might even help extend a woman's reproductive life, by preventing eggs being used up when she doesn't want to conceive, he added.