BBC News Online: Sci/Tech

Male contraceptive 'could fight STDs'

They believe it may be possible to develop a drug that will block sperm production and fight infections, including HIV.

The potential target for drug action is a natural anti-bacterial chemical involved in sperm production and storage.

The substance has been found in rats, but seems to have equivalents in humans and chimps.

The new findings, by a team at the Chinese Academy of Sciences, Shanghai, and the Chinese University of Hong Kong, are reported in the journal Science.

Anti-STD target

The researchers identified a peptide, or protein particle, that operates in a male rat's epididymis, an organ in its testicles involved in sperm production.

The scientists said the peptide, called Bin1b, was found to suppress the growth of the common E. coli bacteria. This, the researchers said, suggested the peptide acted as a line of defence in the male organ.

But they think the peptide may also be involved in nurturing sperm. Thus, the peptide might form the basis for a drug that worked as a contraceptive and as a microbicide to protect against disease.

They write in the journal Science: "Taken together, Bin1b appears to have different roles in epididymis function and may not only offer an interesting lead for work in contraception but may also have therapeutic implications for sexually transmitted diseases."