Tests on rats have shown that an experimental male contraceptive drug blocks connections to cells which feed the developing sperm – making the male infertile, say American and Italian scientists. As fairly low doses of the drug are needed, no significant side-effects were detected.

The scientists said the infertility is not permanent, as soon as treatment stops the male is soon fertile again. They added that further studies are needed to find out whether the drug is as effective and safe with human males.

You can read about this research in the journal Nature Medicine.

In order for sperm to grow and become mature, they need to be located next to Sertoli cells. Sertoli cells nurse the sperm and aid their development. The scientists wanted to see whether it was possible to break the connection between the sperm and the Sertoli cells.

In order to disconnect the two (sperm and Sertoli cells), the researchers used Adjudin, a new molecule. However, Adjudin is toxic if too much is applied. To keep the dosage low, Adjudin was linked to inactive FSH, a hormone. The inactive FSH carried the low-dose Adjudin directly to the area where it could effectively block communication between the sperm and Sertoli cells. This resulted in the male rats not being able to reproduce.

Team leader, Dr. D Mruk, the Center For Biomedical Research, New York, believes they have found a drug which could eventually become a male contraceptive pill.

“A male contraceptive targeting germ cell adhesion”
Dolores D Mruk, Ching-Hang Wong, Bruno Silvestrini & C Yan Cheng
Nature Medicine Published online: 29 October 2006; doi:10.1038/nm1420
Click here to see abstract online

Written by: Christian Nordqvist
Editor: Medical News Today