Male contraceptives

Lewis, D. H., Tice, T. R., and Beck, L. R., Overview of controlled release systems for male contraception, in Male Contraception Advances and Future Prospects (G. I. Zatuchni, ed.). Harper and Row, Philadelphia, 1986, pp. 336-345. 

The concept of torsional asymmetry is not jnst an interesting abstract idea. Some years ago, fertility in some Chinese rnral commnnities was found to be below normal levels, and this was traced back to the presence of gossypol in dietary cottonseed oil. Gossypol acts as a male contraceptive, altering sperm matnration, spermatozoid motility, and inactivation of sperm enzymes necessary for fertilization. Extensive trials in China have shown the antifertility effect is reversible after stopping the treatment, and it has potential, therefore, as a contraceptive for men. 

Unlabeled Uses Hyperlipidemia, lung cancer, male contraception, malnutrition, postmenopausal osteoporosis, rheumatoid arthritis, Sjogren s syndrome, trauma/sur-... 

It is to be expected that these extremely widely used oral methods of contraception will eventually be replaced by luteinizing hormone analogs as antiovulatory agents, or possibly by immunological methods directed against human chorionic gonadotrophin (hCG), which has both LH and FSH activity. Prostaglandins also show promise, and reliable male contraception is also a future possibility. 

Male contraception, involving the suppression of spermatogenesis, is an intensely investigated area, but there have been few positive results that could be used on a practical... 

The one product obtained from cottonseed oil, Gossypol which is categorized as non-hormonal selective spermatogenesis suppressant, is effective in producing azoospermia or severe oligospermia but it is not widely used as male contraceptive. Mechanism of action is not known. Adverse effects are edema, diarrhoea, hypokalemia, neuritis. 

Verapamil has been shown to block the P-glycoprotein responsible for the transport of many foreign drugs out of cancer (and other) cells (see Chapter 1) other calcium channel blockers appear to have a similar effect. This action is not stereospecific. Verapamil has been shown to partially reverse the resistance of cancer cells to many chemotherapeutic drugs in vitro. Some clinical results suggest similar effects in patients (see Chapter 54). Animal research suggests possible future roles of calcium blockers in the treatment of osteoporosis, fertility disorders and male contraception, immune modulation, and even schistosomiasis. 

THE TESTIS (ANDROGENS ANABOLIC STEROIDS, ANTIANDROGENS, MALE CONTRACEPTION)... 

Bebb RA, Anawalt BD, Christensen RB, Paulsen CA, Bremner WJ, Matsumoto AM. Combined administration of levonorgestrel and testosterone induces more rapid and effective suppression of spermatogenesis than testosterone alone a promising male contraceptive approach. J Clin Endocrinol Metab 1996 81(2) 757-62. 

Wu FC, Balasubramanian R, Mulders TM, Coelingh-Bennink HJ. Oral progestogen combined with testosterone as a potential male contraceptive additive effects between... 

The Testis (Androgens Anabolic Steroids, Antiandrogens, Male Contraception)... 

W. C. Ford, Progress Towards a Male Contraceptive., Wiley, New York, 1982, p. 159. 

AO/FRS - scavenges O9, lipid peroxvl radicals 4- Fe(II)-induced lipid peroxidation (1) (Ca -ATPasc, CAMA, CDPK, 110HSDH, MLCK, PKA, PKC) [antifungal, antitumour, inhibits spermatogenesis, male contraceptive]... 

For male contraception androgens are under trial they inhibit pituitary gonadotrophin production and have a direct testicular action. 

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