Scientists say a new male contraceptive could be available within the next 10 years, after they have discovered a way to block sperm transportation following ejaculation. This is according to a study published in the journal Proceedings of the National Academy of Sciences.
The researchers, led by Dr. Sab Ventura and Dr. Carl White of the Monash Institute of Pharmaceutical Sciences in Australia, say that the search for a viable male contraceptive target is something that has been challenging the medical world for many years, but many strategies have failed due to long-term effects on male fertility.
“Most strategies have focused on hormonal or germ-line strategies to produce dysfunctional sperm that are incapable of fertilization,” say the investigators.
“The problem with such approaches is that they have intolerable side effects, such as affecting male sexual activity or causing long-term irreversible effects on fertility. In addition, some strategies may transmit detrimental changes to future offspring.”
But the researchers say they have discovered a male contraceptive target within the autonomic nervous system – a control system that affects sexual arousal, among other functions.
Using a mouse model, the team found that the absence of two proteins on the smooth muscle cells that prompt sperm transportation after ejaculation – α1A-adrenoceptor and P2X1-purinoceptor – could achieve “complete male infertility.”
Furthermore, the investigators say that blocking these proteins had no long-term effects on the sexual behavior or function of the male mice.
Explaining their findings, Dr. Ventura says:
“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.”
The researchers believe this approach could be used to develop a contraceptive pill for men, and if successful, the pill could be available within the next 10 years.
“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,” says Dr. Ventura.
He notes that a drug already exists that has the ability to block one of the two proteins, but that they need to find a chemical and develop a drug that is able to block the other protein.
Last year, Medical News Today reported on a study detailing another potential way to block sperm movement using a compound called JQ1.