For years scientists have researched male contraceptives. However, many of the methods discovered permanently affect male fertility or come with negative side effects and consequences. Now, through a new study involving male mice, it’s been found that the key to temporary and reversible male infertility may lie in blocking two key proteins that transport sperm during ejaculation.

The new study was recently published in the journal Proceedings of the National Academy of Science. During the study, scientists found that the two proteins, α1A-adrenoceptor and P2X1-purinoceptor, may hold the key to a viable male contraceptive. These proteins are responsible for the triggering of sperm during ejaculation. However, when blocked they successfully cause male infertility without lasting side effects. The proteins are found in the smooth muscle cells, and during the tests with lab mice, the proteins were successfully blocked with an orally administered drug compound.

Lead researchers, Dr. Sab Ventura and Dr. Carl White of the Monash Institute of Pharmaceutical Sciences, are confident that the same drugs used to block the proteins in the mice can be made into a contraceptive pill for men.

"Previous strategies have focused on hormonal targets or mechanisms that produce dysfunctional sperm incapable of fertilization, but they often interfere with male sexual activity and cause long term irreversible effects on fertility," Dr. Ventura said. "We've shown that simultaneously disrupting the two proteins that control the transport of sperm during ejaculation causes complete male infertility, but without affecting the long-term viability of sperm or the sexual or general health of males. The sperm is effectively there but the muscle is just not receiving the chemical message to move it.”

Right now, there is already viable drug that blocks one of the proteins, but researchers and scientists now have to find a chemical that successfully blocks the other in order to create the contraceptive pill. Dr. Ventura says that "this suggests a therapeutic target for male contraception. The next step is to look at developing an oral male contraceptive drug, which is effective, safe, and readily reversible."

The original research team as well as researchers from the University of Melbourne and the University of Leicester, UK, believe that a male contraceptive pill that is safe and reversible could be formed and available within 10 years if a successful chemical is found.

Monash University (2013, December 3). Dual protein knockout could lead to new male contraceptive. ScienceDaily.