Peptide fragments of the protein laminin-gamma3 temporarily halt production of sperm cells when injected into rat testes reports a study published in Nature Communications this week. The work may prove to be the first step in the development of a potential male contraceptive.
Transient changes in the leakiness of a tissue known as the blood-testis barrier are important for proper production of sperm cells and regulated by the protein laminin-gamma3. Yan Cheng and his team identified the regions within the laminin-gamma3 protein that were responsible for this effect. They then went on to show that injections of synthetic peptides corresponding to these laminin-gamma3 fragments into testes disrupted the blood-testis barrier in rats, which impaired sperm production. The effect eased off after the injection, with sperm production returning to normal levels about four months after treatment.
It currently remains unclear, however, whether the injections also reduced the fertility of rats and whether these peptides would have the same effect in humans.