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Thought I would post this since it was an easy cut and paste to a thread I replied to on another board.
Contraception. 2002 Apr;65(4):259-63. Related Articles, Links
Gossypol: a contraceptive for men.
Coutinho EM.
School of Medicine, Federal University of Bahia, Salvador, Bahia, Brazil. [email protected]
Gossypol is a polyphenol isolated from the seed, roots, and stem of the cotton plant (Gossypium sp.). The substance, a yellow pigment similar to flavonoids, is present in cottonseed oil. In the plant, it acts as a natural defensive agent against predators, provoking infertility in insects. In most animals, gossypol provokes infertility, and in man it causes spermatogenesis arrest at relatively low doses. Studies carried out in China, Africa, and Brazil have shown that the substance is well tolerated, causing no side effects that lead to discontinuation. The reported hypokalemia of early studies has not been confirmed in the latest trials. The only concern at present appears to be lack of reversibility in over 20% of subjects. Gossypol should be prescribed preferably to men who have completed their families or for those who would accept permanent infertility after a few years of use.
1: IRCS J Med Sci. 1980 Jun;8(6):375-6. Related Articles, Links
Studies on the male antifertility agent gossypol acetic acid: in vitro studies on the effect of gossypol acetic acid on human spermatozoa.
Kalla NR, Vasudev M.
PIP: The hypothesis that gossypol (an active ingredient associated with cottonseed oil) affects enzymes and other constituents of spermatozoa, resulting in alterations in motility and sperm viability after in vitro treatment, was tested using human semen samples. At a gossypol acetic acid concentration (and a 30 minute incubation) of .01 mcg, the percent motility was 71+ or -2.5 (P .01); at .1 mcg concentration, percent motility was 69+ or -4 (P .01); at 1 mcg motility was 66+ or -5 (P .005); at 10 cg, motility was 38.5+ or -3.5 (P .001). Control values for sperm motility were 77+ or -3. These investigations suggested that treatment with gossypol depletes production of adenosine triphosphate in the sperms and thus their metabolism does not proceed normally, rendering them immotile. It appears that the high vulnerability of the testis to gossypol and the uncoupling of oxidative phosphorylation in the respiratory chain of mitochondria of germ cells may be the mechanism responsible for infertility induction.
PMID: 12336803 [PubMed - indexed for MEDLINE]
: Fertil Steril. 1981 Nov;36(5):638-42. Related Articles, Links
Testosterone and gossypol effects on human sperm motility.
Ridley AJ, Blasco L.
Testosterone concentration in seminal fluid has been found to be high in infertile males (75 +/- 11 pg/100 microliter). Fertile males have a testosterone concentration of 29 +/- 3 pg/100 microliter. The effects of adding 50, 150, and 300 pg of testosterone to 100 microliter of ejaculate have been studied by turbidimetric analysis (Sokoloski J, et al. Fertil Steril 28:1337, 1977). This method permits objective measurements of sperm velocity and percentage of rapidly moving sperm in a sample (%RM). A dose-dependent effect of testosterone on sperm motility was seen. Fifty pg/100 microliter had no effect on velocity or percentage of moving sperm; 150 pg of testosterone produced a decrease of 36% +/- 8; and 300 pg/100 microliter, a decrease of 62% +/- 8. Caffeine had a stimulatory effect on the percentage of motile sperm at doses of 400 microliter of semen. Likewise, dibutyryl cAMP (10 microgram/microliter) had a positive effect on sperm velocity. The stimulatory effect of these two drugs were negated when 300 pg of testosterone was added to the preparations. Other steroids (17 alpha-testosterone, 17 alpha-estradiol, and 17 beta-estradiol, DHT, and progesterone) tested under the same experimental conditions had no effect on sperm motility, but cottonseed oil (goosypol) had drastic effects. Doses a little as 100 pg/100 microliter produced a 90% decrease in sperm motility.
PMID: 6273239 [PubMed - indexed for MEDLINE]
Fertil Steril. 1996 Apr;65(4):821-9. Related Articles, Links
Erratum in:
Fertil Steril 1996 Jun;65(6):1267.
Contraceptive efficacy of testosterone-induced azoospermia and oligozoospermia in normal men.
[No authors listed]
World Health Organization, Geneva, Switzerland.
OBJECTIVE: To determine contraceptive efficacy of hormonally induced sperm suppression to severe oligozoospermia or azoospermia. DESIGN: Prospective, noncomparative contraceptive efficacy study. SETTING: Multicenter study in 15 centers in nine countries. PARTICIPANTS: Three hundred ninety-nine normal, healthy, fertile men requesting a male contraceptive method. INTERVENTION: Weekly IM injection of 200 mg T enanthate. MAIN OUTCOME MEASURE: Incidence of pregnancies in efficacy when couples relied on T injections alone for contraception. RESULTS: Four pregnancies occurred during 49.5 person-years involving men with oligozoospermia (0.1 to 3 x 10(6)/mL) and none during 230.4 person-years in azoospermic men: pregnancy rates 8.1 (95 percent confidence interval [CI] 2.2 to 20.7) and 0.0 (95 percent CI, 0.0 to 1.6) per 100 person-years, respectively, or 1.4 (95 percent CI, 0.4 to 3.7) per 100 person-years for oligozoospermia and azoospermia (O to 3 x 10(6)/mL) combined. Pregnancy rates were related to sperm concentration. Inadequate suppression of spermatogenesis occurred in eight men and escape from suppression occurred in four. Discontinuations were due to personal reasons (50 men, cumulative annual life-table rate 12.2 percent [95 percent CI, 9.1 percent to 16.1 percent]) and dislike of the injection schedule (21 men, 5.1 percent [95 percent CI, 3.2 percent to 7.9 percent]). Thirty-five men discontinued for medical reasons (9.4 percent [95 percent CI, 6.7 percent to 13.2 percent]), with no serious treatment-related side effects. After stopping injections, sperm output recovered; additionally, fertility was demonstrated in 33 couples. CONCLUSION: Suppression of spermatogenesis to azoospermia or severe oligozoospermia (< or = 3 x 10(6)/mL) induced by weekly T enanthate injections results in sustained, reversible contraception with good efficacy and minimal short-term side effects. New hormonal regimens with more convenient delivery and improved spermatogenic suppression would provide practical male contraception.
Publication Types:
Clinical Trial
Multicenter Study
PMID: 8654646 [PubMed - indexed for MEDLINE]
Network. 1992 Aug;13(1):20-3. Related Articles, Links
Looking for the "male pill".
Herndon N.
PIP: Researchers are pursuing 2 approaches to developing a male contraceptive drug. 1 approach centers around suppression of sperm production the other around blocking conception. Researchers are looking at introducing hormonal contraceptives into men's bodies via injections or implants to stop sperm production. Both forms of these possible male contraceptives will not be available for many years, however. A WHO study on testosterone enanthate of men in 7 countries reveals total suppression of sperm production occurred in almost all the Asian men, but only about 60% suppression occurred in other ethnic groups. A current WHO study is examining whether a hormonal contraceptive which is not 100% effective can be useful if it would be more effective than barrier methods. The Population Council is conducting research on 2 capsule implants with 1 capsule releasing luteinizing hormone releasing hormone 13 to halt sperm production while the other releases an androgen to maintain sex drive. Animal tests indicate complete contraception with no side effects. The other possible means of suppressing sperm production is administration of a cottonseed oil extract called gossypol which appears to stop sperm production thereby eliminating the need for concurrent androgen administration. Yet it does cause potassium depletion in some men which can result in arrhythmias. An antifertility vaccine comprises the 2nd approach. Several US researchers are exploring an antifertility vaccine to produce antibodies only to the specialized sperm surface needed to attach to the egg. The 1st antifertility vaccine would probably be in pill form and a woman's contraceptive since it is earlier to target the smaller number of sperm in the oviduct than in the testes.
PMID: 12317724 [PubMed - indexed for MEDLINE]
Contraception. 2002 Apr;65(4):259-63. Related Articles, Links
Gossypol: a contraceptive for men.
Coutinho EM.
School of Medicine, Federal University of Bahia, Salvador, Bahia, Brazil. [email protected]
Gossypol is a polyphenol isolated from the seed, roots, and stem of the cotton plant (Gossypium sp.). The substance, a yellow pigment similar to flavonoids, is present in cottonseed oil. In the plant, it acts as a natural defensive agent against predators, provoking infertility in insects. In most animals, gossypol provokes infertility, and in man it causes spermatogenesis arrest at relatively low doses. Studies carried out in China, Africa, and Brazil have shown that the substance is well tolerated, causing no side effects that lead to discontinuation. The reported hypokalemia of early studies has not been confirmed in the latest trials. The only concern at present appears to be lack of reversibility in over 20% of subjects. Gossypol should be prescribed preferably to men who have completed their families or for those who would accept permanent infertility after a few years of use.
1: IRCS J Med Sci. 1980 Jun;8(6):375-6. Related Articles, Links
Studies on the male antifertility agent gossypol acetic acid: in vitro studies on the effect of gossypol acetic acid on human spermatozoa.
Kalla NR, Vasudev M.
PIP: The hypothesis that gossypol (an active ingredient associated with cottonseed oil) affects enzymes and other constituents of spermatozoa, resulting in alterations in motility and sperm viability after in vitro treatment, was tested using human semen samples. At a gossypol acetic acid concentration (and a 30 minute incubation) of .01 mcg, the percent motility was 71+ or -2.5 (P .01); at .1 mcg concentration, percent motility was 69+ or -4 (P .01); at 1 mcg motility was 66+ or -5 (P .005); at 10 cg, motility was 38.5+ or -3.5 (P .001). Control values for sperm motility were 77+ or -3. These investigations suggested that treatment with gossypol depletes production of adenosine triphosphate in the sperms and thus their metabolism does not proceed normally, rendering them immotile. It appears that the high vulnerability of the testis to gossypol and the uncoupling of oxidative phosphorylation in the respiratory chain of mitochondria of germ cells may be the mechanism responsible for infertility induction.
PMID: 12336803 [PubMed - indexed for MEDLINE]
: Fertil Steril. 1981 Nov;36(5):638-42. Related Articles, Links
Testosterone and gossypol effects on human sperm motility.
Ridley AJ, Blasco L.
Testosterone concentration in seminal fluid has been found to be high in infertile males (75 +/- 11 pg/100 microliter). Fertile males have a testosterone concentration of 29 +/- 3 pg/100 microliter. The effects of adding 50, 150, and 300 pg of testosterone to 100 microliter of ejaculate have been studied by turbidimetric analysis (Sokoloski J, et al. Fertil Steril 28:1337, 1977). This method permits objective measurements of sperm velocity and percentage of rapidly moving sperm in a sample (%RM). A dose-dependent effect of testosterone on sperm motility was seen. Fifty pg/100 microliter had no effect on velocity or percentage of moving sperm; 150 pg of testosterone produced a decrease of 36% +/- 8; and 300 pg/100 microliter, a decrease of 62% +/- 8. Caffeine had a stimulatory effect on the percentage of motile sperm at doses of 400 microliter of semen. Likewise, dibutyryl cAMP (10 microgram/microliter) had a positive effect on sperm velocity. The stimulatory effect of these two drugs were negated when 300 pg of testosterone was added to the preparations. Other steroids (17 alpha-testosterone, 17 alpha-estradiol, and 17 beta-estradiol, DHT, and progesterone) tested under the same experimental conditions had no effect on sperm motility, but cottonseed oil (goosypol) had drastic effects. Doses a little as 100 pg/100 microliter produced a 90% decrease in sperm motility.
PMID: 6273239 [PubMed - indexed for MEDLINE]
Fertil Steril. 1996 Apr;65(4):821-9. Related Articles, Links
Erratum in:
Fertil Steril 1996 Jun;65(6):1267.
Contraceptive efficacy of testosterone-induced azoospermia and oligozoospermia in normal men.
[No authors listed]
World Health Organization, Geneva, Switzerland.
OBJECTIVE: To determine contraceptive efficacy of hormonally induced sperm suppression to severe oligozoospermia or azoospermia. DESIGN: Prospective, noncomparative contraceptive efficacy study. SETTING: Multicenter study in 15 centers in nine countries. PARTICIPANTS: Three hundred ninety-nine normal, healthy, fertile men requesting a male contraceptive method. INTERVENTION: Weekly IM injection of 200 mg T enanthate. MAIN OUTCOME MEASURE: Incidence of pregnancies in efficacy when couples relied on T injections alone for contraception. RESULTS: Four pregnancies occurred during 49.5 person-years involving men with oligozoospermia (0.1 to 3 x 10(6)/mL) and none during 230.4 person-years in azoospermic men: pregnancy rates 8.1 (95 percent confidence interval [CI] 2.2 to 20.7) and 0.0 (95 percent CI, 0.0 to 1.6) per 100 person-years, respectively, or 1.4 (95 percent CI, 0.4 to 3.7) per 100 person-years for oligozoospermia and azoospermia (O to 3 x 10(6)/mL) combined. Pregnancy rates were related to sperm concentration. Inadequate suppression of spermatogenesis occurred in eight men and escape from suppression occurred in four. Discontinuations were due to personal reasons (50 men, cumulative annual life-table rate 12.2 percent [95 percent CI, 9.1 percent to 16.1 percent]) and dislike of the injection schedule (21 men, 5.1 percent [95 percent CI, 3.2 percent to 7.9 percent]). Thirty-five men discontinued for medical reasons (9.4 percent [95 percent CI, 6.7 percent to 13.2 percent]), with no serious treatment-related side effects. After stopping injections, sperm output recovered; additionally, fertility was demonstrated in 33 couples. CONCLUSION: Suppression of spermatogenesis to azoospermia or severe oligozoospermia (< or = 3 x 10(6)/mL) induced by weekly T enanthate injections results in sustained, reversible contraception with good efficacy and minimal short-term side effects. New hormonal regimens with more convenient delivery and improved spermatogenic suppression would provide practical male contraception.
Publication Types:
Clinical Trial
Multicenter Study
PMID: 8654646 [PubMed - indexed for MEDLINE]
Network. 1992 Aug;13(1):20-3. Related Articles, Links
Looking for the "male pill".
Herndon N.
PIP: Researchers are pursuing 2 approaches to developing a male contraceptive drug. 1 approach centers around suppression of sperm production the other around blocking conception. Researchers are looking at introducing hormonal contraceptives into men's bodies via injections or implants to stop sperm production. Both forms of these possible male contraceptives will not be available for many years, however. A WHO study on testosterone enanthate of men in 7 countries reveals total suppression of sperm production occurred in almost all the Asian men, but only about 60% suppression occurred in other ethnic groups. A current WHO study is examining whether a hormonal contraceptive which is not 100% effective can be useful if it would be more effective than barrier methods. The Population Council is conducting research on 2 capsule implants with 1 capsule releasing luteinizing hormone releasing hormone 13 to halt sperm production while the other releases an androgen to maintain sex drive. Animal tests indicate complete contraception with no side effects. The other possible means of suppressing sperm production is administration of a cottonseed oil extract called gossypol which appears to stop sperm production thereby eliminating the need for concurrent androgen administration. Yet it does cause potassium depletion in some men which can result in arrhythmias. An antifertility vaccine comprises the 2nd approach. Several US researchers are exploring an antifertility vaccine to produce antibodies only to the specialized sperm surface needed to attach to the egg. The 1st antifertility vaccine would probably be in pill form and a woman's contraceptive since it is earlier to target the smaller number of sperm in the oviduct than in the testes.
PMID: 12317724 [PubMed - indexed for MEDLINE]
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