Sperm tap

A male contraceptive pill may only be a few years away, if research at the University of Leicester comes to fruitition.

Richard Evans, Catrin Pritchard and their colleagues at GlaxoWellcome and elsewhere have discovered a way of blocking the path of sperm from the testes, which could produce semen that is virtually sperm free without the need for an irreversible vasectomy. On the other hand, the control they have discovered could also be used to enhance the movement of sperm from the testes and so may have potential in male fertility treatment too.

The approach carried out so far in experimental mice did not affect their sex lives but resulted in only 13% of matings leading to pregnancy compared to the usual 100%.

The control involves the P2X1 receptor in the vas deferens, the tubes that carry sperm from the testes. The receptor is necessary for contractions that move the sperm so a pill to block this receptor stops the contractions and so could be used as a reversible chemical vasectomy.

Nature, 2000, 403, 86.

^* Articles that provide a link to a particular paper will usually take you direct to the paper, although you may need a subscription or to make a pay-per-view to the journal to access the full text. For more information on any of the publishers and how to subscribe to any journals cited in RR please go direct to the publisher's home page (www.nature.com).