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Results for “Sperm Maturation Blocking Agents”

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At least 19 recordsLinked to original sources
PubMed1976

Sequential histopathological and biochemical events in rat caput epididymis after alpha monochlorohydrin administration.

This paper presents sequential histological, histochemical and biochemical changes in rat caput epididymis after a single 100 mg/kg oral dose of alpha chlorohydrin. Desquamation of caput epithelium occurs as early as two days after drug treatment. The caput epididymis is blocked because of accumulation of testicular fluid containing exfoliated immature testicular cells and caput epithelium. There was no effect of drug on motility and morphology of spermatozoa examined from different segments of epididymis and vas deferens. Marked decrease in acid and alkaline phosphatases, nucleic acids and proteins have been registered after drug treatment. On the contrary increase in SDH, cholesterol and glycogen was observed after drug treatment. Decrease in phospholipids in initial stages has also been observed.

Acid Phosphatase↗
PubMed1988

Clinical experience with gossypol in non-Chinese men: a follow-up.

Gossypol monoacetic acid was administered to 12 Brazilian volunteers. The initial dose was 20 mg daily for 4 months. The dose was then reduced to 60 mg weekly (20 mg three times weekly). A significant reduction in sperm motility was detected in all subjects. An increase in the number of immature cells in the ejaculate was also detected in all subjects. Severe oligospermia or azoospermia developed in all subjects at the end of the loading phase. Two years following discontinuation, 3 men were still azoospermic. Only 1 man who was azoospermic 2 years after discontinuation had a late (3 years) recovery. Two of the 3 men who were subjected to high spermatic vein ligation because of varicocele remained azoospermic 2 years after the operation. The third patient, who did not have the operation, also remained azoospermic. Of the 9 patients who recovered, 3 had fathered children during the last 2 years.

Contraceptive Agents, Male↗
PubMed1980

Medium dose cyproterone acetate (CPA): effects on hormone secretion and on spermatogenesis in men.

Medium dose cyproterone acetate (CPA; 10 mg daily p.o.) was administered to 10 fertile men for 12 weeks. Hormonal measurements and semen analyses were performed before, during (4th and 12th week) and after CPA treatment. At the hypothalamo-pituitary level CPA significantly reduced the hypophyseal storage and synthesis capacity for gonadotropins. Basal LH and FSH concentrations were suppressed by 30% and 40%, respectively; while basal prolactin was elevated by 75%. The episodic fluctuations of peripheral gonadotropins remained unaffected. At the testicular level CPA significantly decreased basal testosterone and dihydrotestosterone concentrations by 70% and 50%, respectively. The pulsatile pattern of androgen secretion was abolished. CPA also inhibited spermatogenesis and motility. No serious clinical side effects were observed. All changes appeared to be completely reversible. It is concluded that medium dose CPA induces progestational/anti-gonadotropic effects at the hypothalamo-pituitary level in addition to its antiandrogenic action at the testicular level.

Adult↗
PubMed1976

Determinantion of testosterone concentration in semen of men with normal or subnormal sperm counts and after vasectomy.

Semen from 58 male subjects, aged 22 to 50, was assayed on an individual basis to determine whether T was present in it. Of the subjects examined 23 were normospermic, 14 oligospermic and 9 azoospermic; 12 men had undergone vasectomy were also included in the study. In 39 of the subjects plasma testosterone was estimated. A competitive protein binding technique was employed for T assays while dried extracts of semen were examined by combined gas-chromatography-mass spectrometry and mass fragmentography. Measurable amounts of T were detected in all seminal specimens assayed. This was confirmed by gas chromatography-mass spectrometry which showed a spectrum suggestive of T. The ratio of unconjugated to conjugated steroid in semen was found to be approximately 1:10. Levels of unconjgated T were similar to those found in plasma of normally menstruating women. The mean seminal concentration of unconjugated T (+/-SD) in the specimens assayed was 0.71 ng/ml+/-0.08 for the normospermic, 0.79+/-0.14 for the ezoospermic, 0.69+/-0.09 for the oligospermic, but only 0.38+/-0.04 for the vasectomized subjects. Plasma levels for this androgen were within the range found in normal men of comparable age. Significant correlation between plasma and seminal T concentration could not be demonstrated and there was no correlation between either of the above parameters and the seminal volume, the number, abnormal form percentage and the motility of spermatozooa in the normo--or oligospermic group. However, when the two groups were pooled into one, significant correlations were found between plasma, (but not seminal T concentration) and the seminal characters examined, perhaps suggesting the number of specimens from the groups should be increased to obtain valid data. Administration of human chorionic gonadotropin produced a marked plasma response as well as a rise of seminal T levels in 3 normospermic subjects whereas cyproterone acetate caused reduction of plasm T levels but had no consistent effect on the seminal concentration of ts steroid although the sensitivity of the seminal method may not have detected smaller changes at this level.

Adult↗
PubMed1980

Use of low-dosage oral cyproterone acetate as a male contraceptive.

To ascertain the effects of low-dosage cyproterone acetate (CPA) on the reproductive and endocrine functions of normal men, 25 volunteers were given CPA 0, 5 or 10 mg daily over 16 weeks, preceded by 12 weeks pretreatment observation and followed by 24 weeks posttreatment follow-up. CPA caused a decrease in sperm concentration, percentage motility, proportion of normal sperm and ability of the sperm to penetrate a column of cervical mucus in most patients. In addition, circulating testosterone, estradiol, LH and FSH levels were significantly reduced during treatment. All these changes reverted to the pretreatment level upon drug withdrawal. These findings suggest that firstly, although low dosage CPA was able to induce changes in seminal analyses, azoospermia was present in only one out of 15 subjects exposed to the drug. Secondly, the marked decrease in androgen levels associated with CPA treatment renders CPA unsuitable as a single entity agent for long-term male contraception.

Adult↗
PubMed1977

Effect of short-term cyclic administration of cyproterone acetate on pituitary-ovarian function in the human.

Short courses of cyproterone acetate, a compound with progestational and antiandrogenic activities, were administered to normally menstruating women during different phases of the menstrual cycle to suppress growth and maturation of the follicles and corpus luteum function. Postovulatory administration of 20 mg of the drug daily for 8 days to two women delayed menstruation by 4 to 6 days, followed by prolonged bleeding and short post-treatment cycles. Plasma levels of progesterone were suppressed temporarily during therapy, but increased immediately after cessation of treatment. Administration of 10 mg of the drug for 8 days during the early follicular phase to two women resulted in irregular bleeding, short cycles, and decreased plasma levels of progesterone throughout the cycle. Reduction of the dose to 2.5 mg during the early follicular phase in two other women also resulted in irregular cycles. When the 2.5-mg dose was administered to three women from the 8th to the 15th days of the cycle, vaginal bleeding and cycle length were normal. Plasma levels of luteinizing hormone and progesterone were suppressed during therapy. In one subject, cervical mucus was found to be hostile to sperm penetration in all three treatment cycles. The results indicate that, with cyclic administration of low doses of cyproterone acetate to women during the late follicular phase, it may be possible to interrupt pituitary-ovarian function, as well as sperm transport through the cervical mucus.

Body Temperature↗
PubMed1989

Nonhormonal mediation of male reproductive tract damage: data from contraceptive drug research.

Chemicals can interfere with hormonal control of the male reproductive tract and/or directly alter male reproductive tract function. A review is presented of those chemicals developed and tested as male contraceptive agents which have a direct effect on the male reproductive tract with minimal disturbance of the hormonal milieu. Such chemicals can have one or more sites of action: 1) the testis, disturbing spermatogenesis; 2) the epididymis, altering sperm maturation; 3) the vas deferens, affecting sperm transport; and 4) the accessory sex glands, entering the ejaculate and changing the functional activity of the spermatozoa. Examples of each mode of action are presented.

Animals↗