Monkey's immune system aids scientists to design a new type of &to=http://english.pravda.ru/fun/2002/05/15/28737.html' target=_blank>male contraceptive.
They report that they injected nine male macaque monkeys with Eppin, a protein from the testes. Seven became infertile, and of these five became fertile again when the treatment stopped.
Researchers have been experimenting for years to find reliable male hormonal contraceptives. Some are in clinical trials. But so far the only reliable male choice has been &to=http://english.pravda.ru/main/18/90/363/11967_condom.html' target=_blank>the condom, or vasectomy, reports Guardian.
According to The State, male monkeys that developed a strong immune response to the eppin were still able to copulate but could not impregnate females, the researchers said.
"We don’t understand the exact mechanism yet, but we think the immunocontraception works by preventing the sperm from freeing itself from the seminal fluid to make its way to the uterus and oviducts to fertilize the egg," O’Rand said.
In the experiments, carried out in India, seven of the nine males developed high antibody levels. Five of the seven recovered fertility once the immunization ended.
Dr. Patricia Anastasia DeLeon of the University of Delaware said the results were significant and that scientists were lucky to get a protein that would produce antibodies. Normally the body does not produce antibodies against its own proteins, she said.
But, DeLeon said, the testis and epididymis are protected by a barrier so the protein never gets into the bloodstream. So, when eppin was injected into the bloodstream the immune system did not recognize it and produced antibodies.