Male contraceptive

From Wikipedia, the free encyclopedia

A male contraceptive is a method, device, or drug used by a man that prevents his sperm from conceiving a child with his female partner. The only methods of contraception currently available to men are withdrawal, condoms, and vasectomy. Withdrawal and condoms can be inconvenient, and both suffer from unreliability in typical use. Vasectomies are reliable and have a high satisfaction rate, but are not readily reversible (vasovasostomy).

1 Current research
2 Abandoned research
3 References
4 Further reading
5 See also

[edit] Current research

Prospective future male contraceptives are in various stages of research and development. The ideal method would be highly reliable, reversible, and convenient. A variety of avenues are being researched:

A male oral contraceptive would be a pill that is taken by mouth and absorbed into the blood stream. Some of the male oral contraceptives being investigated are hormonal; most are not.
A male hormonal contraceptive would be a small implanted device placed under the skin, an injection into muscle which releases contraceptive drug into the blood stream over a period of weeks to months, or a gel applied to the skin daily.<ref>Nuzzo R (2006) Beyond condoms: male hormonal contraceptives may finally be on track. Los Angeles Times, 16 October.</ref>
Interference with the maturation of sperm in the epididymis, which is the long, coiled tube through which sperm pass after exiting the testes.<ref>Turner TT, Johnston DS, Jelinsky SA (2006) Epididymal genomics and the search for a male contraceptive Journal of Molecular and Cellular Endocrinology. Released as an Epub ahead of printing on 1 February 2006.</ref><ref>Gottwald U, Davies B, Fritsch M, Habenicht UF (2006) New approaches for male fertility control: HE6 as an example of a putative target Journal of Molecular and Cellular Endocrinology. Released as an Epub ahead of printing on 23 January 2006.

</ref> Drugs targeting this phase of sperm development would become effective faster. Two pharmaceuticals are testing small, easily synthesized drug compound candidates.^{[citation needed]}

RISUG
Partially or completely blocking the vas deferens, the tubes connecting the epididymis to the urethra. While a vasectomy removes a piece of each vas deferens, the intra vas device (IVD) and other injectable plugs only block the tubes until the devices are removed.^{[citation needed]}
Other new male contraceptives act once the sperm have entered the female reproductive tract. Some interfere with the sperms’ ability to swim properly, while others prevent sperm from recognizing or binding to an egg.^{[citation needed]}
Heat-based contraception involves heating the testicles to a high temperature for a short period of time to prevent the formation of sperm. While some very small studies have found certain heating regimines to be effective and reversible,^{[citation needed]} there is currently no interest in funding larger studies.
Papaya seed extract. Compounds derived from papaya seeds and ingested by males immobilize and kill sperm in animal tests, and in vitro human tests — with no toxicity, no side effects, and no decrease in testosterone. The effects take 90 days, and are completely reversible.<ref>Lohiya, NK et al. (2000) Human sperm immobilization effect of Carica papaya seed extracts: an in vitro study Asian Journal of Andrology 2(2): 103-9.</ref><ref>Lohiya, NK et al. (2006) Toxicological investigations on the methanol sub-fraction of the seeds of Carica papaya as a male contraceptive in albino rats Reproductive Toxicology 22(3): 461-8.</ref>
Adjudin — a new non-toxic analog of lonidamine — causes reversible infertility in rats.^{[citation needed]} The drug disrupts the junctions between nurse cells (Sertoli cells) in the testes and forming spermatids. The sperm are released prematurely and never become functional gametes. A new targeted delivery mechanism has made Adjudin much more effective.<ref>Mruk DD, Wong CH, Silvestrini B, Cheng CH (2006) A male contraceptive targeting germ cell adhesion Nature Medicine advance access 29 October 2006.</ref>

[edit] Abandoned research

Gossypol, derived from cotton seeds, was used in trials by the Chinese government for about fifteen years. While was found to be a reliable contraceptive, it has serious health effects, and ten to twenty percent of users become permanently sterile. Research on it as a temporary contraceptive has been abandoned.
Zavesca (aka Miglustat or NB-DNJ) is a drug approved for treatment of several rare lipid storage disorder diseases. In mice, it provided effective and fully reversible contraception. But it seems this effect was only true for several genetically related strains of laboratory mice. Zavesca showed no contraceptive effect in other mammals.<ref>Amory JK, Muller CH, Page ST, Leifke E, Pagel ER, Bhandari A, Subramanyam B, Bone W, Radlmaier A, Bremner WJ. Miglustat has no apparent effect on spermatogenesis in normal men. Human Reproduction advance access 25 October 2006.</ref>