Scientists discover way to create 1 male contraceptive

Sperm rats are inflexible because calcineurin deficiency in semen and therefore infertile



Researchers at Osaka University in Japan have identified a protein found in semen that is responsible for the penetration of sperm into the egg and therefore responsible for fertilize it. The discovery paved the way for the creation of male contraceptive world's first and also to expand the treatments for infertility. The study was published on Thursday (1) in the journal Science.

The protein is called calcineurin and is connected to the calcium transport in the body. Calcineurin is present in various cell types, since the sperm cells to lymphocytes of the immune system.

Scientists led by Masahito Ikawa managed to isolate the specific type that is present in sperm. This type of calcineurin is directly linked to the mobility of gamete. When there is impairment, the intermediate part of the sperm tail can not bend and so can not have the momentum necessary to penetrate the membrane that protects the egg, although usually able to swim.

With genetic engineering techniques, Professor Haruhiko Miyata created calcineurin deficient mice in semen and found that these males were infertile. The staff also found that wild-type mice treated with calcineurin inhibitors - as cyclosporin and FK506 - become sterile in two weeks. After a week without ingesting inhibitors, they returned to be fertile again. This research should pave the way for creating a drug that inhibits the protein responsible for the penetration of sperm into the egg.

Isolation of genes

Previous data showed that calcineurin had an important role in male fertility, but the existence of different types of this protein in the testes made it difficult to learn the function of each. The merit of these scientists was to find out what kinds cast by PPP3CC and PPP3R2 genes are found only in cells that form sperm and so study them.

The group found that the specific calcineurin semen is also present in humans. However, cyclosporin and FK506 can not be used as contraceptives in humans, they also prevent the action of calcineurin present in lymphocytes (antibody).

In cases of organ transplant, for example, doctors use these inhibitors to decrease the risk of rejection of the new organ.

The development of a drug that may only affect the specific calcineurin the sperm can be the key to creating the first with reversible male contraceptive effect in a short time.