New Zealand researchers have shown kisseptin, a small protein molecule in brain, is a key for ovulation in adults. This should help find new fertility treatments.
In 2003, researchers found that the then recently discovered kisspeptin was a crucial trigger for puberty. It is perhaps equally so in the case of ovulation too.
For it has been found that signalling between kisspeptin and its cell receptor GPR54 was essential to activate gonadotrophin-releasing hormone (GnRH) neurons, the nerve cells known to initiate ovulation.
"This is an exciting finding, as people have been trying to find out precisely how the brain controls ovulation for more than 30 years. This work now reveals a crucial link in the brain circuitry responsible," Professor Allan Herbison of Physiology department in Otago said.
The study indicates that disorders affecting the signalling between kisspeptin and the GPR54 receptors will result in women being unable to ovulate, he says.
"Targeting drugs to this chemical switch to make it work properly may help some people who are infertile, while finding compounds that can block this switch could lead to new contraceptives," he says.
As an approach to treating infertility in some women, it could allow for ovulation to be induced in a more natural way than current therapies, he says.
"Kisspeptin activity in the brain occurs at the top level of the cascade of neural and hormonal processes that eventually lead to ovaries releasing eggs. By targeting this switch, the subsequent processes could proceed normally, avoiding the need to induce ovulation by injection of large doses of the hormones themselves," he says.
With infertility becoming an increasing problem for couples in western societies, there is a great deal of interest in developing new therapies, he says.
"Our findings show that kisspeptin may be a promising area to focus future research efforts aimed at either enhancing or regulating human fertility."
Oddly enough, the name kisspeptin is completely unrelated to its association with reproduction, he says.
"The researchers who originally discovered the gene that codes for kisspeptin had no idea that it had a role in fertility - it was named in honour of Hershey Kisses, as Hershey was the town in the United States where the scientists were based."
Professor Herbison says his research group is now investigating what role kisspeptin-GPR54 signalling may play in the male reproductive system.