SCIENCE / MEDICINE : New Birth Control Approach

Researchers have found evidence that a tiny protein molecule may play an important role in reproduction in rats, suggesting a possible new approach to contraception and treating infertility in humans.

Investigators at the Yale University School of Medicine found that if they blocked a peptide, or small protein molecule known as angiotensin, in female rats, they were able to interfere with ovulation. If they replaced the peptide, the ovulation blockage was reversed, they said.

Angiotensin has long been known as a molecule that regulates blood pressure and fluid balance in the body, but the scientists have found it is also present in high concentrations in the fluid in the tiny sacs or follicles surrounding ova before they are released. The cells of the follicles have receptors for angiotensin, but until now there was no evidence that it might play some role in regulating the reproductive cycle.

“We think that if you could block angiotensin action in the ovary you might be able to have contraception. If you could mimic it you might be able to increase fertility,” said Dr. Frederick Naftolin, chairman of obstetrics and gynecology, who headed the study published in the journal Science.